795 lines
28 KiB
C++
795 lines
28 KiB
C++
/////////////////////////////////////////////////////////////////////////////////////
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///
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/// ### Things to do:
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///
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/// - [x] Drawing triangles
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/// - [x] Drawing cubes and lines for testing
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/// - [x] Y up coordinate system, left handed
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/// - [x] Drawing a cube with perspective
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/// - [x] Culling triangles facing away from camera
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/// - [x] Texture mapping
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/// - [x] Basic linear transformations - rotation, translation, scaling
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/// - [x] Bilinear filtering of textures
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/// - [x] Nearest filtering
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/// - [x] Fix the gaps between triangles (it also improved look of triangle edges)
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/// - [ ] Perspective matrix vs simple perspective
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/// - [x] Perspective correct interpolation
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/// - [x] Depth buffer
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/// - [x] Gamma correct blending - converting to almost linear space
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/// - [x] Alpha blending
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/// - [x] Premultiplied alpha
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/// - [x] Merge with base
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/// - [ ] Fill convention
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/// - [ ] Antialiasing (seems like performance gets really bad with this)
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/// - [x] LookAt Camera
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/// - [x] FPS Camera
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/// - [ ] Quarternions for rotations
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/// - [x] Reading OBJ models
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/// - [x] Dumping raw obj files
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/// - [x] Loading raw obj files, big startup speedup!
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/// - [ ] Reading more OBJ formats
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/// - [x] Reading OBJ .mtl files
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/// - [x] Loading materials
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/// - [x] Rendering textures obj models
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/// - [x] Reading complex obj models (sponza)
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/// - [x] Fix sponza uv coordinates - the issue was uv > 1 and uv < 0
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/// - [x] Clipping
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/// - [x] Triagnle rectangle bound clipping
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/// - [x] A way of culling Z out triangles
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/// - [x] Simple test z clipping
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/// - [x] Maybe should clip a triangle on znear zfar plane?
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/// - [x] Maybe should clip out triangles that are fully z out before draw_triangle
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/// - [ ] Effects!!!
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/// - [ ] Outlines
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/// - [ ] Lightning
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/// - [ ] Proper normal interpolation
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/// * https://hero.handmade.network/episode/code/day101/#105
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/// - [ ] Phong
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/// - [x] diffuse
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/// - [x] ambient
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/// - [ ] specular
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/// * reflecting vectors
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/// - [ ] Use all materials from OBJ
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/// - [ ] Point light
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/// - [ ] Reading PMX files
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/// - [ ] Rendering multiple objects, queue renderer
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/// - [x] Simple function to render a mesh
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/// - [x] Simple profiling tooling
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/// - [x] Statistics based on profiler data
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/// - [x] Find cool profilers - ExtraSleepy, Vtune
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/// - [ ] Optimizations
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/// - [ ] Inline edge function
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/// - [ ] Expand edge functions to more optimized version
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/// - [ ] Test 4x2 bitmap layout?
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/// - [ ] Edge function to integer
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/// - [ ] Use integer bit operations to figure out if plus. (edge0|edge1|edge2)>=0
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/// - [ ] SIMD
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/// - [ ] Multithreading
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///
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/// - [x] Text rendering
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/// - [ ] UI
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/// - [x] Labels
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/// - [x] Settings variables
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/// - [x] Signals
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/// - [ ] Sliders
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/// - [ ] Groups
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/// - [x] Gamma correct alpha blending for rectangles and bitmaps
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/// - [ ] Plotting of profile data
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/// - [x] Simple scatter plot
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///
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///
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/// ### Urgent:
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///
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/// - [ ] Simplify the code, especially for the 2d routines
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/// - [x] Asset processor as second program
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///
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///
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#define PREMULTIPLIED_ALPHA_BLENDING 1
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#include "multimedia.cpp"
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#include "profile.cpp"
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#include "obj.cpp"
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struct Vertex {
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Vec3 pos;
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Vec2 tex;
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Vec3 norm;
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};
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struct Render {
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Mat4 camera;
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Mat4 projection;
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Mat4 transform;
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Vec3 camera_pos;
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Vec3 camera_direction;
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Vec3 camera_forward_velocity;
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Vec2 camera_yaw;
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Vec3 camera_target;
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Bitmap img;
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B32 plot_ready;
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Bitmap plot;
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Bitmap screen320;
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F32 *depth320;
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};
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enum Scene {
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Scene_F22,
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Scene_Sponza,
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Scene_Count,
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};
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global F32 light_rotation = 0;
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global F32 zfar_value = 100000.f;
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function
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Vec4 srgb_to_almost_linear(Vec4 a) {
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Vec4 result = {a.r*a.r, a.g*a.g, a.b*a.b, a.a};
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return result; // @Note: Linear would be to power of 2.2
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}
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function
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Vec4 almost_linear_to_srgb(Vec4 a) {
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Vec4 result = { sqrtf(a.r), sqrtf(a.g), sqrtf(a.b), a.a };
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return result;
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}
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function
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Vec4 premultiplied_alpha(Vec4 dst, Vec4 src) {
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Vec4 result;
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result.r = src.r + ((1-src.a) * dst.r);
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result.g = src.g + ((1-src.a) * dst.g);
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result.b = src.b + ((1-src.a) * dst.b);
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result.a = src.a + dst.a - src.a*dst.a;
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return result;
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}
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function
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void draw_rect(Bitmap* dst, F32 X, F32 Y, F32 w, F32 h, Vec4 color) {
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int max_x = (int)(min(X + w, (F32)dst->x) + 0.5f);
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int max_y = (int)(min(Y + h, (F32)dst->y) + 0.5f);
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int min_x = (int)(max(0.f, X) + 0.5f);
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int min_y = (int)(max(0.f, Y) + 0.5f);
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color.rgb *= color.a;
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color = srgb_to_almost_linear(color);
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for (int y = min_y; y < max_y; y++) {
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for (int x = min_x; x < max_x; x++) {
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U32 *dst_pixel = dst->pixels + (x + y * dst->x);
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Vec4 dstc = srgb_to_almost_linear(vec4abgr(*dst_pixel));
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dstc = premultiplied_alpha(dstc, color);
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U32 color32 = vec4_to_u32abgr(almost_linear_to_srgb(dstc));
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*dst_pixel = color32;
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}
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}
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}
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function
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void draw_bitmap(Bitmap* dst, Bitmap* src, Vec2 pos, Vec2 size=vec2(F32MAX, F32MAX)) {
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S64 minx = (S64)(pos.x + 0.5);
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S64 miny = (S64)(pos.y + 0.5);
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if (size.x == F32MAX || size.y == F32MAX) {
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S64 maxx = minx + src->x;
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S64 maxy = miny + src->y;
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S64 offsetx = 0;
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S64 offsety = 0;
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if (maxx > dst->x) {
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maxx = dst->x;
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}
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if (maxy > dst->y) {
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maxy = dst->y;
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}
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if (minx < 0) {
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offsetx = -minx;
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minx = 0;
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}
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if (miny < 0) {
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offsety = -miny;
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miny = 0;
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}
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for (S64 y = miny; y < maxy; y++) {
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for (S64 x = minx; x < maxx; x++) {
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S64 tx = x - minx + offsetx;
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S64 ty = y - miny + offsety;
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U32 *dst_pixel = dst->pixels + (x + y * dst->x);
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U32 *pixel = src->pixels + (tx + ty * src->x);
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Vec4 result_color = srgb_to_almost_linear(vec4abgr(*pixel));
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Vec4 dst_color = srgb_to_almost_linear(vec4abgr(*dst_pixel));
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result_color = premultiplied_alpha(dst_color, result_color);
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result_color = almost_linear_to_srgb(result_color);
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U32 color32 = vec4_to_u32abgr(result_color);
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*dst_pixel = color32;
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}
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}
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}
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else {
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S64 maxx = minx + (S64)(size.x + 0.5f);
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S64 maxy = miny + (S64)(size.y + 0.5f);
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S64 offsetx = 0;
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S64 offsety = 0;
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maxx = clamp_top(maxx, (S64)dst->x);
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maxy = clamp_top(maxy, (S64)dst->y);
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if (minx < 0) {
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offsetx = -minx;
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minx = 0;
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}
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if (miny < 0) {
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offsety = -miny;
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miny = 0;
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}
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F32 distx = (F32)(maxx - minx);
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F32 disty = (F32)(maxy - miny);
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for (S64 y = miny; y < maxy; y++) {
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for (S64 x = minx; x < maxx; x++) {
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F32 u = (F32)(x - minx) / distx;
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F32 v = (F32)(y - miny) / disty;
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S64 tx = (S64)(u * src->x + 0.5f);
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S64 ty = (S64)(v * src->y + 0.5f);
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U32 *dst_pixel = dst->pixels + (x + y * dst->x);
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U32 *pixel = src->pixels + (tx + ty * src->x);
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Vec4 result_color = srgb_to_almost_linear(vec4abgr(*pixel));
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Vec4 dst_color = srgb_to_almost_linear(vec4abgr(*dst_pixel));
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result_color = premultiplied_alpha(dst_color, result_color);
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result_color = almost_linear_to_srgb(result_color);
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U32 color32 = vec4_to_u32abgr(result_color);
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*dst_pixel = color32;
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}
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}
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}
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}
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function
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Vec4 base_string(Bitmap *dst, Font *font, String word, Vec2 pos, B32 draw) {
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Vec2 og_position = pos;
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F32 max_x = pos.x;
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for (U64 i = 0; i < word.len; i++) {
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if (word.str[i] == ' ') {
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FontGlyph* g = &font->glyphs['_' - '!'];
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pos.x += g->xadvance;
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if (pos.x > max_x) max_x = pos.x;
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}
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else if (word.str[i] == '\n') {
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pos.y -= font->line_advance;
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pos.x = og_position.x;
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}
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else {
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FontGlyph* g = &font->glyphs[word.str[i] - '!'];
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if(draw) draw_bitmap(dst, &g->bitmap, pos - g->bitmap.align);
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pos.x += g->xadvance;
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if (pos.x > max_x) max_x = pos.x;
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}
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}
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Vec4 rect = vec4(og_position.x, pos.y, max_x - og_position.x, og_position.y - pos.y + font->line_advance);
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return rect;
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}
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function
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Vec4 draw_string(Bitmap *dst, Font *font, String word, Vec2 pos) {
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return base_string(dst, font, word, pos, true);
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}
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function
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Vec4 get_string_rect(Font *font, String word, Vec2 pos) {
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return base_string(0, font, word, pos, false);
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}
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function
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F32 edge_function(Vec4 vecp0, Vec4 vecp1, Vec4 p) {
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F32 result = (vecp1.y - vecp0.y) * (p.x - vecp0.x) - (vecp1.x - vecp0.x) * (p.y - vecp0.y);
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return result;
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}
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function
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void draw_triangle_nearest(Bitmap* dst, F32 *depth_buffer, Bitmap *src, Vec3 light_direction,
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Vec4 p0, Vec4 p1, Vec4 p2,
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Vec2 tex0, Vec2 tex1, Vec2 tex2,
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Vec3 norm0, Vec3 norm1, Vec3 norm2) {
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if(os.frame > 60) PROFILE_BEGIN(draw_triangle);
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F32 min_x1 = (F32)(min(p0.x, min(p1.x, p2.x)));
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F32 min_y1 = (F32)(min(p0.y, min(p1.y, p2.y)));
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F32 max_x1 = (F32)(max(p0.x, max(p1.x, p2.x)));
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F32 max_y1 = (F32)(max(p0.y, max(p1.y, p2.y)));
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S64 min_x = (S64)max(0.f, floor(min_x1));
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S64 min_y = (S64)max(0.f, floor(min_y1));
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S64 max_x = (S64)min((F32)dst->x, ceil(max_x1));
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S64 max_y = (S64)min((F32)dst->y, ceil(max_y1));
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F32 dy10 = (p1.y - p0.y);
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F32 dy21 = (p2.y - p1.y);
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F32 dy02 = (p0.y - p2.y);
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F32 dx10 = (p1.x - p0.x);
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F32 dx21 = (p2.x - p1.x);
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F32 dx02 = (p0.x - p2.x);
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F32 C0 = dy10 * (p0.x) - dx10 * (p0.y);
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F32 C1 = dy21 * (p1.x) - dx21 * (p1.y);
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F32 C2 = dy02 * (p2.x) - dx02 * (p2.y);
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F32 Cy0 = dy10 * min_x - dx10 * min_y - C0;
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F32 Cy1 = dy21 * min_x - dx21 * min_y - C1;
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F32 Cy2 = dy02 * min_x - dx02 * min_y - C2;
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U32 *destination = dst->pixels + dst->x*min_y;
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F32 area = (p1.y - p0.y) * (p2.x - p0.x) - (p1.x - p0.x) * (p2.y - p0.y);
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for (S64 y = min_y; y < max_y; y++) {
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F32 Cx0 = Cy0;
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F32 Cx1 = Cy1;
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F32 Cx2 = Cy2;
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for (S64 x = min_x; x < max_x; x++) {
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if (Cx0 >= 0 && Cx1 >= 0 && Cx2 >= 0) {
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F32 w1 = Cx1 / area;
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F32 w2 = Cx2 / area;
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F32 w3 = Cx0 / area;
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// @Note: We could do: interpolated_w = 1.f / interpolated_w to get proper depth
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// but why waste an instruction, the smaller the depth value the farther the object
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F32 interpolated_w = (1.f / p0.w) * w1 + (1.f / p1.w) * w2 + (1.f / p2.w) * w3;
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F32* depth = depth_buffer + (x + y * dst->x);
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if (*depth < interpolated_w) {
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*depth = interpolated_w;
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F32 invw0 = (w1 / p0.w);
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F32 invw1 = (w2 / p1.w);
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F32 invw2 = (w3 / p2.w);
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Vec3 norm = (norm0 * invw0 + norm1 * invw1 + norm2 * invw2) / interpolated_w;
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F32 u = tex0.x * invw0 + tex1.x * invw1 + tex2.x * invw2;
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F32 v = tex0.y * invw0 + tex1.y * invw1 + tex2.y * invw2;
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{
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u /= interpolated_w;
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v /= interpolated_w;
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u = u - floor(u);
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v = v - floor(v);
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// u = CLAMP(0, u, 1);
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// v = CLAMP(0, v, 1);
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u = u * (src->x - 1);
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v = v * (src->y - 1);
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}
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S64 ui = (S64)(u);
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S64 vi = (S64)(v);
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//F32 udiff = u - (F32)ui;
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//F32 vdiff = v - (F32)vi;
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// Origin UV (0,0) is in bottom left
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U32 *dst_pixel = destination + x;
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U32 *pixel = src->pixels + (ui + (src->y - 1ll - vi) * src->x);
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#if PREMULTIPLIED_ALPHA_BLENDING
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Vec4 result_color; {
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U32 c = *pixel;
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F32 a = ((c & 0xff000000) >> 24) / 255.f;
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F32 b = ((c & 0x00ff0000) >> 16) / 255.f;
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F32 g = ((c & 0x0000ff00) >> 8) / 255.f;
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F32 r = ((c & 0x000000ff) >> 0) / 255.f;
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r*=r;
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g*=g;
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b*=b;
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result_color = { r,g,b,a };
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}
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Vec4 dst_color; {
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U32 c = *dst_pixel;
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F32 a = ((c & 0xff000000) >> 24) / 255.f;
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F32 b = ((c & 0x00ff0000) >> 16) / 255.f;
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F32 g = ((c & 0x0000ff00) >> 8) / 255.f;
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F32 r = ((c & 0x000000ff) >> 0) / 255.f;
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r*=r; g*=g; b*=b;
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dst_color = { r,g,b,a };
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}
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Vec3 light_color = vec3(0.8,0.8,1);
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constexpr F32 ambient_strength = 0.1f; {
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Vec3 ambient = ambient_strength * light_color;
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Vec3 diffuse = clamp_bot(0.f, -dot(norm, light_direction)) * light_color;
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result_color.rgb *= (ambient+diffuse);
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}
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result_color = premultiplied_alpha(dst_color, result_color);
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result_color = almost_linear_to_srgb(result_color);
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U32 color32 = vec4_to_u32abgr(result_color);
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#else
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U32 color32 = *pixel;
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#endif
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*dst_pixel = color32;
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}
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}
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Cx0 += dy10;
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Cx1 += dy21;
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Cx2 += dy02;
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}
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Cy0 -= dx10;
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Cy1 -= dx21;
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Cy2 -= dx02;
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destination += dst->x;
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}
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if(os.frame > 60) PROFILE_END(draw_triangle);
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}
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function
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void draw_triangle_bilinear(Bitmap* dst, F32 *depth_buffer, Bitmap *src, Vec3 light_direction,
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Vec4 p0, Vec4 p1, Vec4 p2,
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Vec2 tex0, Vec2 tex1, Vec2 tex2,
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Vec3 norm0, Vec3 norm1, Vec3 norm2) {
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F32 min_x1 = (F32)(min(p0.x, min(p1.x, p2.x)));
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F32 min_y1 = (F32)(min(p0.y, min(p1.y, p2.y)));
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F32 max_x1 = (F32)(max(p0.x, max(p1.x, p2.x)));
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F32 max_y1 = (F32)(max(p0.y, max(p1.y, p2.y)));
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S64 min_x = (S64)clamp_bot(0.f, floor(min_x1));
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S64 min_y = (S64)clamp_bot(0.f, floor(min_y1));
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S64 max_x = (S64)clamp_top((F32)dst->x, ceil(max_x1));
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S64 max_y = (S64)clamp_top((F32)dst->y, ceil(max_y1));
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F32 area = edge_function(p0, p1, p2);
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for (S64 y = min_y; y < max_y; y++) {
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for (S64 x = min_x; x < max_x; x++) {
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F32 edge0 = edge_function(p0, p1, { (F32)x,(F32)y });
|
|
F32 edge1 = edge_function(p1, p2, { (F32)x,(F32)y });
|
|
F32 edge2 = edge_function(p2, p0, { (F32)x,(F32)y });
|
|
|
|
if (edge0 >= 0 && edge1 >= 0 && edge2 >= 0) {
|
|
F32 w1 = edge1 / area;
|
|
F32 w2 = edge2 / area;
|
|
F32 w3 = edge0 / area;
|
|
F32 interpolated_w = (1.f / p0.w) * w1 + (1.f / p1.w) * w2 + (1.f / p2.w) * w3;
|
|
|
|
F32 u = tex0.x * (w1 / p0.w) + tex1.x * (w2 / p1.w) + tex2.x * (w3 / p2.w);
|
|
F32 v = tex0.y * (w1 / p0.w) + tex1.y * (w2 / p1.w) + tex2.y * (w3 / p2.w);
|
|
|
|
u /= interpolated_w;
|
|
v /= interpolated_w;
|
|
// @Note: We could do: interpolated_w = 1.f / interpolated_w to get proper depth
|
|
// but why waste an instruction, the smaller the depth value the farther the object
|
|
F32* depth = depth_buffer + (x + y * dst->x);
|
|
if (*depth < interpolated_w && interpolated_w > 0.1f) {
|
|
*depth = interpolated_w;
|
|
u = u * (src->x - 2);
|
|
v = v * (src->y - 2);
|
|
S64 ui = (S64)(u);
|
|
S64 vi = (S64)(v);
|
|
F32 udiff = u - (F32)ui;
|
|
F32 vdiff = v - (F32)vi;
|
|
// Origin UV (0,0) is in bottom left
|
|
U32 *pixel = src->pixels + (ui + (src->y - 1ll - vi) * src->x);
|
|
U32 *dst_pixel = dst->pixels + (x + y * dst->x);
|
|
|
|
Vec4 pixelx1y1 = vec4abgr(*pixel);
|
|
Vec4 pixelx2y1 = vec4abgr(*(pixel + 1));
|
|
Vec4 pixelx1y2 = vec4abgr(*(pixel - src->x));
|
|
Vec4 pixelx2y2 = vec4abgr(*(pixel + 1 - src->x));
|
|
pixelx1y1 = srgb_to_almost_linear(pixelx1y1);
|
|
pixelx2y1 = srgb_to_almost_linear(pixelx2y1);
|
|
pixelx1y2 = srgb_to_almost_linear(pixelx1y2);
|
|
pixelx2y2 = srgb_to_almost_linear(pixelx2y2);
|
|
Vec4 blendx1 = lerp(pixelx1y1, pixelx2y1, udiff);
|
|
Vec4 blendx2 = lerp(pixelx1y2, pixelx2y2, udiff);
|
|
Vec4 result_color = lerp(blendx1, blendx2, vdiff);
|
|
|
|
#if 0
|
|
result_color.r *= light;
|
|
result_color.g *= light;
|
|
result_color.b *= light;
|
|
#endif
|
|
#if PREMULTIPLIED_ALPHA_BLENDING
|
|
Vec4 dst_color = vec4abgr(*dst_pixel);
|
|
dst_color = srgb_to_almost_linear(dst_color);
|
|
result_color = premultiplied_alpha(dst_color, result_color);
|
|
#endif // PREMULTIPLIED_ALPHA_BLENDING
|
|
result_color = almost_linear_to_srgb(result_color);
|
|
U32 color32 = vec4_to_u32abgr(result_color);
|
|
|
|
*dst_pixel = color32;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
function
|
|
void draw_mesh(Render *r, String scene_name, Obj_Material *materials, Obj_Mesh *mesh, Vec3 *vertices, Vec2 *tex_coords, Vec3 *normals) {
|
|
for (int i = 0; i < mesh->indices.len; i++) {
|
|
Obj_Index *index = mesh->indices.data + i;
|
|
Bitmap *image = &r->img;
|
|
if(index->material_id != -1) {
|
|
Obj_Material *material = materials + index->material_id;
|
|
// @Todo: No size info from OBJ things, this stuff needs a bit of refactor
|
|
// Need to figure out how to accomodate multiple possible formats of input etc.
|
|
if(material->texture_ambient.pixels) {
|
|
image = &material->texture_ambient;
|
|
}
|
|
}
|
|
Vertex vert[] = {
|
|
{
|
|
vertices[index->vertex[0] - 1],
|
|
tex_coords[index->tex[0] - 1],
|
|
normals[index->normal[0] - 1],
|
|
},
|
|
{
|
|
vertices[index->vertex[1] - 1],
|
|
tex_coords[index->tex[1] - 1],
|
|
normals[index->normal[1] - 1],
|
|
},
|
|
{
|
|
vertices[index->vertex[2] - 1],
|
|
tex_coords[index->tex[2] - 1],
|
|
normals[index->normal[2] - 1],
|
|
},
|
|
};
|
|
|
|
//@Note: Transform
|
|
for (int j = 0; j < 3; j++) {
|
|
vert[j].pos = r->transform * vert[j].pos;
|
|
}
|
|
|
|
|
|
Vec3 p0_to_camera = r->camera_pos - vert[0].pos;
|
|
Vec3 p0_to_p1 = vert[1].pos - vert[0].pos;
|
|
Vec3 p0_to_p2 = vert[2].pos - vert[0].pos;
|
|
Vec3 normal = normalize(cross(p0_to_p1, p0_to_p2));
|
|
Vec3 light_direction = mat4_rotation_x(light_rotation) * vec3(0, 0, 1);
|
|
|
|
if (dot(normal, p0_to_camera) > 0) { //@Note: Backface culling
|
|
/// ## Clipping
|
|
///
|
|
/// There are 3 clipping stages, 2 clipping stages in 3D space against zfar and znear and 1 clipping
|
|
/// stage in 2D against left, bottom, right, top(2D image bounds).
|
|
///
|
|
/// First the triangles get clipped against the zfar plane,
|
|
/// if a triangle has even one vertex outside the clipping region, the entire triangle gets cut.
|
|
/// So far I didn't have problems with that. It simplifies the computations and splitting triangles
|
|
/// on zfar seems like a waste of power.
|
|
///
|
|
/// The second clipping stage is znear plane. Triangles get fully and nicely clipped against znear.
|
|
/// Every time a triangle gets partially outside the clipping region it gets cut to the znear and
|
|
/// either one or two new triangles get derived from the old one.
|
|
///
|
|
/// Last clipping stage is performed in the 2D image space. Every triangle has a corresponding AABB
|
|
/// box. In this box every pixel gets tested to see if it's in the triangle. In this clipping stage
|
|
/// the box is clipped to the image metrics - 0, 0, width, height.
|
|
///
|
|
///
|
|
// @Note: Zfar
|
|
B32 vertex_is_outside = false;
|
|
Vec3 zfar_normal = vec3(0, 0, -1);
|
|
Vec3 zfar_pos = vec3(0, 0, zfar_value);
|
|
for (S32 j = 0; j < 3; j++) {
|
|
// @Note: Camera
|
|
vert[j].pos = r->camera * vert[j].pos;
|
|
// @Note: Skip triangle if even one vertex gets outside the clipping plane
|
|
if ((dot(zfar_normal, vert[j].pos - zfar_pos) < 0)) {
|
|
vertex_is_outside = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (vertex_is_outside) {
|
|
continue;
|
|
}
|
|
|
|
// @Note: Znear, clip triangles to the near clipping plane
|
|
Vec3 znear_normal = vec3(0, 0, 1);
|
|
Vec3 znear_pos = vec3(0, 0, 1.f);
|
|
|
|
struct _Vertex {
|
|
Vec4 pos;
|
|
Vec2 tex;
|
|
Vec3 norm;
|
|
} in[4];
|
|
S32 in_count = 0;
|
|
|
|
Vertex *prev = vert + 2;
|
|
Vertex *curr = vert;
|
|
F32 prev_dot = dot(znear_normal, prev->pos - znear_pos);
|
|
F32 curr_dot = 0;
|
|
for (int j = 0; j < 3; j++) {
|
|
curr_dot = dot(znear_normal, curr->pos - znear_pos);
|
|
if (curr_dot * prev_dot < 0) {
|
|
F32 t = prev_dot / (prev_dot - curr_dot);
|
|
in[in_count].pos = vec4(lerp(prev->pos, curr->pos, t), 1);
|
|
in[in_count].tex = lerp(prev->tex, curr->tex, t);
|
|
in[in_count++].norm = lerp(prev->norm, curr->norm, t);
|
|
}
|
|
if (curr_dot > 0) {
|
|
in[in_count].pos = vec4(vert[j].pos, 1);
|
|
in[in_count].tex = vert[j].tex;
|
|
in[in_count++].norm = vert[j].norm;
|
|
}
|
|
prev = curr++;
|
|
prev_dot = curr_dot;
|
|
}
|
|
|
|
if (in_count == 0) {
|
|
continue;
|
|
}
|
|
|
|
for(S64 j = 0; j < in_count; j++) {
|
|
//@Note: Perspective
|
|
in[j].pos = r->projection * in[j].pos;
|
|
in[j].pos.x = in[j].pos.x / in[j].pos.w;
|
|
in[j].pos.y = in[j].pos.y / in[j].pos.w;
|
|
// in[j].pos.z = in[j].pos.z / in[j].pos.w;
|
|
//@Note: To pixel space
|
|
in[j].pos.x *= r->screen320.x / 2;
|
|
in[j].pos.y *= r->screen320.y / 2;
|
|
in[j].pos.x += r->screen320.x / 2;
|
|
in[j].pos.y += r->screen320.y / 2;
|
|
}
|
|
|
|
|
|
draw_triangle_nearest(&r->screen320, r->depth320, image, light_direction, in[0].pos, in[1].pos, in[2].pos, in[0].tex, in[1].tex, in[2].tex, in[0].norm, in[1].norm, in[2].norm);
|
|
if (in_count > 3) {
|
|
draw_triangle_nearest(&r->screen320, r->depth320, image, light_direction, in[0].pos, in[2].pos, in[3].pos, in[0].tex, in[2].tex, in[3].tex, in[0].norm, in[2].norm, in[3].norm);
|
|
}
|
|
|
|
#if 0
|
|
ProfileScope *scope = profile_scopes + ProfileScopeName_draw_triangle;
|
|
LOCAL_PERSIST B32 profile_flag;
|
|
if (!profile_flag && scope->i > 2000) {
|
|
profile_flag = 1;
|
|
save_profile_data(scope, scene_name, LIT("draw_triangle"));
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
|
|
#include "ui.cpp"
|
|
global F32 speed = 100.f;
|
|
global F32 rotation = 0;
|
|
global Obj *f22;
|
|
global Obj *sponza;
|
|
global Obj *obj;
|
|
global Render r = {};
|
|
global Scene scene = Scene_Sponza;
|
|
|
|
function
|
|
UI_SIGNAL_CALLBACK(scene_callback) {
|
|
switch(scene) {
|
|
case Scene_F22: {
|
|
speed = 1;
|
|
r.camera_pos = vec3(0,0,-2);
|
|
obj = f22;
|
|
} break;
|
|
case Scene_Sponza: {
|
|
speed = 100;
|
|
r.camera_pos = vec3(0,0,-2);
|
|
obj = sponza;
|
|
} break;
|
|
case Scene_Count:
|
|
invalid_default_case;
|
|
}
|
|
scene = (Scene)(((int)scene + 1) % Scene_Count);
|
|
}
|
|
|
|
function void
|
|
windows_log(Log_Kind kind, String string, char *file, int line){
|
|
OutputDebugStringA((char *)string.str);
|
|
}
|
|
|
|
int main(int argc, char **argv) {
|
|
thread_ctx.log_proc = windows_log;
|
|
os.window_size.x = 320*2;
|
|
os.window_size.y = 180*2;
|
|
os.window_resizable = 1;
|
|
assert(os_init());
|
|
Font font = os_load_font(os.perm_arena, 72, "Arial", 0);
|
|
|
|
f22 = load_obj_dump(os.perm_arena, "plane.bin"_s);
|
|
sponza = load_obj_dump(os.perm_arena, "sponza.bin"_s);
|
|
scene_callback();
|
|
|
|
int screen_x = 1280/2;
|
|
int screen_y = 720/2;
|
|
|
|
r.camera_pos = {0,0,-2};
|
|
r.screen320 = {(U32 *)arena_push_size(os.perm_arena, screen_x*screen_y*sizeof(U32)), screen_x, screen_y};
|
|
r.plot = {(U32 *)arena_push_size(os.perm_arena, 1280*720*sizeof(U32)), 1280, 720};
|
|
r.depth320 = (F32 *)arena_push_size(os.perm_arena, sizeof(F32) * screen_x * screen_y);
|
|
//r.img = load_image(""_s);
|
|
|
|
|
|
String frame_data = {};
|
|
UISetup setup[] = {
|
|
UI_SIGNAL("Change scene"_s, scene_callback),
|
|
UI_IMAGE(&r.plot),
|
|
UI_LABEL(&frame_data),
|
|
};
|
|
UI ui = ui_make(setup, buff_cap(setup));
|
|
B32 ui_mouse_lock = true;
|
|
|
|
while (os_game_loop()) {
|
|
|
|
|
|
if (ui_mouse_lock == false) {
|
|
r.camera_yaw.x += os.delta_mouse_pos.x * 0.01f;
|
|
r.camera_yaw.y -= os.delta_mouse_pos.y * 0.01f;
|
|
}
|
|
if (os.key[Key_Escape].pressed) os_quit();
|
|
if (os.key[Key_O].down) light_rotation += 0.05f;
|
|
if (os.key[Key_P].down) light_rotation -= 0.05f;
|
|
if (os.key[Key_F2].pressed) {
|
|
ui_mouse_lock = !ui_mouse_lock;
|
|
os_show_cursor(!os.cursor_visible);
|
|
}
|
|
if (os.key[Key_A].down) r.camera_pos.x -= speed * (F32)os.delta_time;
|
|
if (os.key[Key_D].down) r.camera_pos.x += speed * (F32)os.delta_time;
|
|
if (os.key[Key_W].down) {
|
|
r.camera_forward_velocity = r.camera_direction * speed * (F32)os.delta_time;
|
|
r.camera_pos = r.camera_pos + r.camera_forward_velocity;
|
|
}
|
|
if (os.key[Key_S].down) {
|
|
r.camera_forward_velocity = r.camera_direction * speed * (F32)os.delta_time;
|
|
r.camera_pos = r.camera_pos - r.camera_forward_velocity;
|
|
}
|
|
if (os.key[Key_R].down) r.camera_pos.y += speed * (F32)os.delta_time;
|
|
if (os.key[Key_F].down) r.camera_pos.y -= speed * (F32)os.delta_time;
|
|
U32* p = r.screen320.pixels;
|
|
for (int y = 0; y < r.screen320.y; y++) {
|
|
for (int x = 0; x < r.screen320.x; x++) {
|
|
*p++ = 0x33333333;
|
|
}
|
|
}
|
|
F32* dp = r.depth320;
|
|
for (int y = 0; y < r.screen320.y; y++) {
|
|
for (int x = 0; x < r.screen320.x; x++) {
|
|
*dp++ = -F32MAX;
|
|
}
|
|
}
|
|
|
|
|
|
Mat4 camera_rotation = mat4_rotation_y(r.camera_yaw.x) * mat4_rotation_x(r.camera_yaw.y);
|
|
r.camera_direction = (camera_rotation * vec4(0,0,1,1)).xyz;
|
|
Vec3 target = r.camera_pos + r.camera_direction;
|
|
r.camera = mat4_look_at(r.camera_pos, target, vec3(0, 1, 0));
|
|
r.projection = mat4_perspective(60.f, (F32)os.screen->x, (F32)os.screen->y, 1.f, zfar_value);
|
|
r.transform = mat4_rotation_z(rotation);
|
|
r.transform = r.transform * mat4_rotation_y(rotation);
|
|
for (int i = 0; i < obj->mesh.len; i++) {
|
|
Vec2* tex_coords = (Vec2*)obj->texture_coordinates.data;
|
|
Vec3 *normals = (Vec3 *)obj->normals.data;
|
|
Obj_Mesh *mesh = obj->mesh.data;
|
|
Vec3* vertices = (Vec3 *)obj->vertices.data;
|
|
draw_mesh(&r, obj->name, obj->materials.data, mesh+i, vertices, tex_coords, normals);
|
|
}
|
|
|
|
|
|
// @Note: Draw 320screen to OS screen
|
|
U32* ptr = os.screen->pixels;
|
|
for (int y = 0; y < os.screen->y; y++) {
|
|
for (int x = 0; x < os.screen->x; x++) {
|
|
F32 u = (F32)x / (F32)os.screen->x;
|
|
F32 v = (F32)y / (F32)os.screen->y;
|
|
int tx = (int)(u * r.screen320.x );
|
|
int ty = (int)(v * r.screen320.y );
|
|
*ptr++ = r.screen320.pixels[tx + ty * (r.screen320.x)];
|
|
}
|
|
}
|
|
ui_end_frame(os.screen, &ui, &font);
|
|
frame_data = string_fmt(os.frame_arena, "FPS:%f dt:%f frame:%u", os.fps, os.delta_time, os.frame);
|
|
}
|
|
}
|
|
|
|
/////////////////////////////////////////////////////////////////////////////////////
|
|
/// ### Resources that helped me build the rasterizer (Might be helpful to you too):
|
|
///
|
|
/// * Algorithm I used for triangle rasterization by Juan Pineda is described in paper called "A Parallel Algorithm for Polygon Rasterization"
|
|
/// * Casey Muratori's series on making a game from scratch(including a 2D software rasterizer(episode ~82) and 3d gpu renderer): https://hero.handmade.network/episode/code#
|
|
/// * Fabian Giessen's "Optimizing Software Occlusion Culling": https://fgiesen.wordpress.com/2013/02/17/optimizing-sw-occlusion-culling-index/
|
|
/// * Fabian Giessen's optimized software renderer: https://github.com/rygorous/intel_occlusion_cull/tree/blog/SoftwareOcclusionCulling
|
|
/// * Fabian Giessen's javascript triangle rasterizer: https://gist.github.com/rygorous/2486101
|
|
/// * Fabian Giessen's C++ triangle rasterizer: https://github.com/rygorous/trirast/blob/master/main.cpp
|
|
/// * Joy's Kenneth lectures about computer graphics: https://www.youtube.com/playlist?list=PL_w_qWAQZtAZhtzPI5pkAtcUVgmzdAP8g
|
|
/// * Joy's Kenneth article on clipping: https://import.cdn.thinkific.com/167815/JoyKennethClipping-200905-175314.pdf
|
|
/// * A bunch of helpful notes and links to resources: https://nlguillemot.wordpress.com/2016/07/10/rasterizer-notes/
|
|
/// * Very nice paid course on making a software rasterizer using a scanline method: https://pikuma.com/courses/learn-3d-computer-graphics-programming
|
|
/// * Reference for obj loader: https://github.com/tinyobjloader/tinyobjloader/blob/master/tiny_obj_loader.h
|
|
///
|
|
/// ### To read
|
|
///
|
|
/// * http://ce-publications.et.tudelft.nl/publications/1362_hardware_algorithms_for_tilebased_realtime_rendering.pdf
|