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Global ilumination

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This commit is contained in:
Krzosa Karol
2022-02-20 20:49:55 +01:00
parent 03777764b7
commit 4b6cd41c01
3 changed files with 69 additions and 60 deletions
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105
main.cpp
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@@ -13,8 +13,8 @@ OK Fix the gaps between triangles (it also improved look of triangle edges)
OK Perspective correct interpolation
OK Depth buffer
KINDA_OK Gamma correct blending
* Alpha blending??
* Premultiplied alpha???
OK Alpha blending??
OK Premultiplied alpha???
* Lightning
* LookAt Camera
* FPS Camera
@@ -61,32 +61,6 @@ struct Face {
Vec2 tex[3];
};
GLOBAL Vec3 cube_vertices[] = {
{-1, -1,-1},
{-1, 1, -1},
{1, 1, -1},
{1, -1, -1},
{1, 1, 1},
{1, -1, 1},
{-1, 1, 1},
{-1, -1,1},
};
GLOBAL Face cube_faces[] = {
{{1, 2, 3}, {{ 0, 0 }, { 0, 1 }, { 1, 1 }}, },
{{1, 3, 4}, {{ 0, 0 }, { 1, 1 }, { 1, 0 }}, },
{{4, 3, 5}, {{ 0, 0 }, { 0, 1 }, { 1, 1 }}, },
{{4, 5, 6}, {{ 0, 0 }, { 1, 1 }, { 1, 0 }}, },
{{6, 5, 7}, {{ 0, 0 }, { 0, 1 }, { 1, 1 }}, },
{{6, 7, 8}, {{ 0, 0 }, { 1, 1 }, { 1, 0 }}, },
{{8, 7, 2}, {{ 0, 0 }, { 0, 1 }, { 1, 1 }}, },
{{8, 2, 1}, {{ 0, 0 }, { 1, 1 }, { 1, 0 }}, },
{{2, 7, 5}, {{ 0, 0 }, { 0, 1 }, { 1, 1 }}, },
{{2, 5, 3}, {{ 0, 0 }, { 1, 1 }, { 1, 0 }}, },
{{6, 8, 1}, {{ 0, 0 }, { 0, 1 }, { 1, 1 }}, },
{{6, 1, 4}, {{ 0, 0 }, { 1, 1 }, { 1, 0 }}, }
};
FUNCTION
void draw_rect(Image* dst, float X, float Y, float w, float h, U32 color) {
int max_x = (int)(MIN(X + w, dst->x) + 0.5f);
@@ -101,6 +75,24 @@ void draw_rect(Image* dst, float X, float Y, float w, float h, U32 color) {
}
}
FUNCTION
float edge_function(Vec4 vecp0, Vec4 vecp1, Vec4 p) {
float result = (vecp1.y - vecp0.y) * (p.x - vecp0.x) - (vecp1.x - vecp0.x) * (p.y - vecp0.y);
return result;
}
FUNCTION
Vec4 srgb_to_almost_linear(Vec4 a) {
Vec4 result = {a.r*a.r, a.g*a.g, a.b*a.b, a.a};
return result; // @Note: Linear would be to power of 2.2
}
FUNCTION
Vec4 almost_linear_to_srgb(Vec4 a) {
Vec4 result = { sqrt(a.r), sqrt(a.g), sqrt(a.b), a.a };
return result;
}
FUNCTION
void draw_bitmap(Image* dst, Image* src, Vec2 pos) {
I64 minx = (I64)(pos.x + 0.5);
@@ -129,31 +121,23 @@ void draw_bitmap(Image* dst, Image* src, Vec2 pos) {
for (I64 x = minx; x < maxx; x++) {
I64 tx = x - minx + offsetx;
I64 ty = y - miny + offsety;
dst->pixels[x + y * dst->x] = src->pixels[tx + ty * src->x];
U32 *dst_pixel = dst->pixels + (x + y * dst->x);
U32 *pixel = src->pixels + (tx + ty * src->x);
Vec4 result_color = srgb_to_almost_linear(vec4abgr(*pixel));
Vec4 dst_color = srgb_to_almost_linear(vec4abgr(*dst_pixel));
result_color.r = result_color.r + (1-result_color.a) * dst_color.r;
result_color.g = result_color.g + (1-result_color.a) * dst_color.g;
result_color.b = result_color.b + (1-result_color.a) * dst_color.b;
result_color.a = result_color.a + dst_color.a - result_color.a*dst_color.a;
result_color = almost_linear_to_srgb(result_color);
U32 color32 = color_to_u32abgr(result_color);
*dst_pixel = color32;
}
}
}
FUNCTION
float edge_function(Vec4 vecp0, Vec4 vecp1, Vec4 p) {
float result = (vecp1.y - vecp0.y) * (p.x - vecp0.x) - (vecp1.x - vecp0.x) * (p.y - vecp0.y);
return result;
}
FUNCTION
Vec4 srgb_to_almost_linear(Vec4 a) {
Vec4 result = {a.r*a.r, a.g*a.g, a.b*a.b, a.a};
return result; // @Note: Linear would be to power of 2.2
}
FUNCTION
Vec4 almost_linear_to_srgb(Vec4 a) {
Vec4 result = { sqrt(a.r), sqrt(a.g), sqrt(a.b), a.a };
return result;
}
FUNCTION
void draw_triangle(Image* dst, float *depth_buffer, Image *src,
void draw_triangle(Image* dst, float *depth_buffer, Image *src, float light,
Vec4 p0, Vec4 p1, Vec4 p2,
Vec2 tex0, Vec2 tex1, Vec2 tex2) {
float min_x1 = (float)(MIN(p0.x, MIN(p1.x, p2.x)));
@@ -215,6 +199,9 @@ void draw_triangle(Image* dst, float *depth_buffer, Image *src,
Vec4 blendx1 = lerp(pixelx1y1, pixelx2y1, udiff);
Vec4 blendx2 = lerp(pixelx1y2, pixelx2y2, udiff);
Vec4 result_color = lerp(blendx1, blendx2, vdiff);
result_color.r *= light;
result_color.g *= light;
result_color.b *= light;
#if PREMULTIPLIED_ALPHA_BLENDING
Vec4 dst_color = vec4abgr(*dst_pixel);
#if GAMMA_CORRECT_BLENDING
@@ -227,7 +214,7 @@ void draw_triangle(Image* dst, float *depth_buffer, Image *src,
#endif // PREMULTIPLIED_ALPHA_BLENDING
#if GAMMA_CORRECT_BLENDING
result_color = almost_linear_to_srgb(result_color);
ASSERT(result_color.r <= 1 && result_color.g <= 1 && result_color.b <= 1);
//ASSERT(result_color.r <= 1 && result_color.g <= 1 && result_color.b <= 1);
#endif // GAMMA_CORRECT_BLENDING
U32 color32 = color_to_u32abgr(result_color);
#else // BILINEAR_BLEND
@@ -313,16 +300,16 @@ int main() {
float rotation = 0;
Vec3 camera_pos = {0,0,-5};
Obj obj = load_obj("assets/cube.obj");
Obj obj = load_obj("assets/f22.obj");
Vec3* vertices = (Vec3 *)obj.vertices;
Vec2* tex_coords = (Vec2*)obj.texture;
FaceA* faces = (FaceA*)obj.indices;
I64 face_count = obj.indices_count;
Image img = load_image("assets/cat.png");
int screen_x = 160;
int screen_y = 90;
Image img = load_image("assets/bricksx64.png");
int screen_x = 320;
int screen_y = 180;
Image screen320 = {(U32 *)malloc(screen_x*screen_y*sizeof(U32)), screen_x, screen_y};
float* depth320 = (float *)malloc(sizeof(float) * screen_x * screen_y);
while (os.game_loop()) {
@@ -330,7 +317,7 @@ int main() {
U32* p = screen320.pixels;
for (int y = 0; y < screen320.y; y++) {
for (int x = 0; x < screen320.x; x++) {
*p++ = 0x44444444;
*p++ = 0x33333333;
}
}
float* dp = depth320;
@@ -339,7 +326,7 @@ int main() {
*dp++ = -FLT_MAX;
}
}
//draw_bitmap(&screen320, &img, {0,0});
Mat4 transform = make_matrix_rotation_z(rotation);
transform = transform * make_matrix_rotation_x(rotation);
if (os.keydown_a) rotation += 0.05f;
@@ -367,7 +354,9 @@ int main() {
Vec3 p0_to_camera = camera_pos - pos[0].xyz;
Vec3 p0_to_p1 = pos[1].xyz - pos[0].xyz;
Vec3 p0_to_p2 = pos[2].xyz - pos[0].xyz;
Vec3 normal = cross(p0_to_p1, p0_to_p2);
Vec3 normal = normalize(cross(p0_to_p1, p0_to_p2));
float light = -dot(normal, vec3(0,1,0));
light = CLAMP(0.05, light, 1);
if (dot(normal, p0_to_camera) > 0) {
for (int j = 0; j < 3; j++) {
//@Note: Camera
@@ -384,12 +373,12 @@ int main() {
pos[j].y += screen320.y / 2;
}
draw_triangle(&screen320, depth320, &img, pos[0], pos[1], pos[2], tex[0], tex[1], tex[2]);
draw_triangle(&screen320, depth320, &img, light, pos[0], pos[1], pos[2], tex[0], tex[1], tex[2]);
for (int j = 0; j < 3; j++) {
pos[j].x += screen320.x / 8;
pos[j].y += screen320.y / 8;
}
draw_triangle(&screen320, depth320, &img, pos[0], pos[1], pos[2], tex[0], tex[1], tex[2]);
draw_triangle(&screen320, depth320, &img, light, pos[0], pos[1], pos[2], tex[0], tex[1], tex[2]);
if (draw_wireframe) {
draw_line(&screen320, pos[0].x, pos[0].y, pos[1].x, pos[1].y);
draw_line(&screen320, pos[1].x, pos[1].y, pos[2].x, pos[2].y);

1
main.h
View File

@@ -5,6 +5,7 @@
#define GLOBAL static
#define MIN(x,y) ((x)>(y)?(y):(x))
#define MAX(x,y) ((x)>(y)?(x):(y))
#define CLAMP(min,x,max) MAX(min,MIN(max, x))
#define ABS(x) ((x)<0?-(x):(x))
#include <stdint.h>
typedef int64_t I64;

19
math.h
View File

@@ -28,6 +28,12 @@ Vec4 vec4(Vec3 a, float b) {
return result;
}
FUNCTION
Vec3 vec3(float x, float y, float z) {
Vec3 result = { x,y,z };
return result;
}
FUNCTION
Mat4 make_matrix_identity() {
Mat4 result = {
@@ -259,6 +265,19 @@ Vec3 cross(Vec3 a, Vec3 b) {
return result;
}
FUNCTION
float length(Vec3 a) {
float result = sqrt(a.x*a.x + a.y*a.y + a.z*a.z);
return result;
}
FUNCTION
Vec3 normalize(Vec3 a) {
float len = length(a);
Vec3 result = {a.x/len, a.y/len, a.z/len};
return result;
}
FUNCTION
U32 color_to_u32argb(Vec4 a) {
uint8_t r8 = (uint8_t)(a.r * 255.f);