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Opengl render and font

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This commit is contained in:
Krzosa Karol
2024-07-26 14:47:03 +02:00
parent ee6df45e2d
commit def8b6bdc2
5 changed files with 362 additions and 38 deletions
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28
src/basic/math.cpp
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@@ -3,6 +3,34 @@ struct Vec2 {
float y;
};
union Vec4 {
struct {
float x;
float y;
float z;
float w;
};
struct {
float r;
float g;
float b;
float a;
};
};
union Vec3 {
struct {
float x;
float y;
float z;
};
struct {
float r;
float g;
float b;
};
};
struct Rect2 {
Vec2 min;
Vec2 max;

38
src/new_platform/font.cpp
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@@ -1,9 +1,9 @@
struct Glyph {
Vec2I size;
Vec2I offset;
int32_t xadvance;
int32_t left_side_bearing;
Rect2 atlas_bounding_box;
Vec2 size;
Vec2 offset;
float xadvance;
float left_side_bearing;
Rect2 atlas_bounding_box;
};
struct Font {
@@ -11,10 +11,10 @@ struct Font {
uint32_t first_char, last_char;
uint32_t texture_id;
int32_t size;
int32_t descent;
int32_t ascent;
int32_t line_gap;
float size;
float descent;
float ascent;
float line_gap;
Rect2 white_texture_bounding_box;
};
@@ -104,15 +104,15 @@ Font CreateFont(Atlas *atlas, int32_t size, String path) {
return result;
}
float scale = stbtt_ScaleForPixelHeight(&stb_font, (float)result.size);
float em_scale = stbtt_ScaleForMappingEmToPixels(&stb_font, (float)result.size);
float scale = stbtt_ScaleForPixelHeight(&stb_font, (float)size);
float em_scale = stbtt_ScaleForMappingEmToPixels(&stb_font, (float)size);
int ascent, descent, line_gap;
stbtt_GetFontVMetrics(&stb_font, &ascent, &descent, &line_gap);
result.ascent = (int32_t)((float)ascent * scale);
result.descent = (int32_t)((float)descent * scale);
result.line_gap = (int32_t)((float)line_gap * scale);
result.size = size;
result.ascent = (float)ascent * scale;
result.descent = (float)descent * scale;
result.line_gap = (float)line_gap * scale;
result.size = (float)size;
result.first_char = ' ';
result.last_char = '~';
result.white_texture_bounding_box = atlas->white_texture_bounding_box;
@@ -127,10 +127,10 @@ Font CreateFont(Atlas *atlas, int32_t size, String path) {
Glyph glyph = {};
glyph.atlas_bounding_box = PackBitmap(atlas, bitmap, width, height);
glyph.size = {width, height};
glyph.offset = {xoff, yoff};
glyph.xadvance = (int32_t)((float)xadvance * scale);
glyph.left_side_bearing = (int32_t)((float)left_side_bearing * scale);
glyph.size = {(float)width, (float)height};
glyph.offset = {(float)xoff, (float)yoff};
glyph.xadvance = (float)xadvance * scale;
glyph.left_side_bearing = (float)left_side_bearing * scale;
Add(&result.glyphs, glyph);
}

45
src/new_platform/new_platform.cpp
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@@ -10,6 +10,7 @@
#include "basic/math_int.cpp"
#include "basic/math.cpp"
#include "font.cpp"
#include "render_opengl.cpp"
bool AppIsRunning = true;
@@ -69,11 +70,11 @@ int main()
return 1;
}
const char *glsl_version = "#version 130";
const char *glsl_version = "#version 450";
SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
@@ -95,30 +96,40 @@ int main()
return 1;
}
SDL_GL_SetSwapInterval(1); // vsync
glDebugMessageCallback(&GLDebugCallback, NULL);
glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
Arena Perm = {};
InitArena(&Perm);
Atlas atlas = CreateAtlas(Perm, {1024, 1024});
Font font = CreateFont(&atlas, 16, "c:\\Windows\\Fonts\\consola.ttf");
{
glCreateTextures(GL_TEXTURE_2D, 1, &atlas.texture_id);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTextureStorage2D(atlas.texture_id, 1, GL_R8, (GLsizei)atlas.size.x, (GLsizei)atlas.size.y);
glTextureSubImage2D(atlas.texture_id, 0, 0, 0, (GLsizei)atlas.size.x, (GLsizei)atlas.size.y, GL_RED, GL_UNSIGNED_BYTE, atlas.bitmap);
Scratch scratch;
Atlas atlas = CreateAtlas(scratch, {1024, 1024});
MainFont = CreateFont(&atlas, 16, "C:\\Windows\\Fonts\\consola.ttf");
{
glCreateTextures(GL_TEXTURE_2D, 1, &atlas.texture_id);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTextureParameteri(atlas.texture_id, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTextureStorage2D(atlas.texture_id, 1, GL_R8, (GLsizei)atlas.size.x, (GLsizei)atlas.size.y);
glTextureSubImage2D(atlas.texture_id, 0, 0, 0, (GLsizei)atlas.size.x, (GLsizei)atlas.size.y, GL_RED, GL_UNSIGNED_BYTE, atlas.bitmap);
}
MainFont.texture_id = atlas.texture_id;
}
font.texture_id = atlas.texture_id;
InitRender();
while (AppIsRunning) {
glClearColor(255, 255, 255, 255);
glClear(GL_COLOR_BUFFER_BIT);
int window_x, window_y;
SDL_GetWindowSize(window, &window_x, &window_y);
Vec2 window_size = {(float)window_x, (float)window_y};
SDL_Event event;
SDL_WaitEvent(&event);
ProcessSDLEvent(&event);
BeginFrameRender(window_size);
DrawString(&MainFont, L"Testing", {0, 0}, {255, 0, 0, 255});
EndFrameRender({0, 0, 0, 1});
SDL_GL_SwapWindow(window);
}

285
src/new_platform/render_opengl.cpp Normal file
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@@ -0,0 +1,285 @@
struct Shader {
uint32_t pipeline;
uint32_t fshader;
uint32_t vshader;
};
Shader CreateShader(char *glsl_vshader, char *glsl_fshader);
struct Color {
uint8_t r;
uint8_t g;
uint8_t b;
uint8_t a;
};
struct Vertex2D {
Vec2 pos;
Vec2 tex;
Color color;
};
struct VertexNode2D {
VertexNode2D *next;
int count;
Vertex2D vertices[1024 * 64];
};
struct VertexList2D {
VertexNode2D *first;
VertexNode2D *last;
};
VertexList2D Vertices;
int64_t TotalVertexCount;
unsigned VBO, VAO;
Shader Shader2D;
Arena RenderArena;
Font MainFont;
Vec2 WindowSize;
void BeginFrameRender(Vec2 window_size) {
Clear(&RenderArena);
TotalVertexCount = 0;
Vertices.first = NULL;
Vertices.last = NULL;
WindowSize = window_size;
}
void EndFrameRender(Vec4 color) {
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glViewport(0, 0, (GLsizei)WindowSize.x, (GLsizei)WindowSize.y);
glClearColor(color.r * 255.f, color.g * 255.f, color.b * 255.f, color.a * 255.f);
glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
// Default draw using the font texture
glBindProgramPipeline(Shader2D.pipeline);
float xinverse = 1.f / (WindowSize.x / 2.f);
float yinverse = 1.f / (WindowSize.y / 2.f);
glProgramUniform2f(Shader2D.vshader, 0, xinverse, yinverse);
for (VertexNode2D *it = Vertices.first; it; it = it->next) {
glNamedBufferSubData(VBO, 0, it->count * sizeof(Vertex2D), it->vertices);
glBindVertexArray(VAO);
GLint s_texture = 0; // texture unit that sampler2D will use in GLSL code
glBindTextureUnit(s_texture, MainFont.texture_id);
glDrawArrays(GL_TRIANGLES, 0, it->count);
}
}
void InitRender() {
InitArena(&RenderArena);
glCreateBuffers(1, &VBO);
glNamedBufferStorage(VBO, Lengthof(VertexNode2D::vertices) * sizeof(Vertex2D), 0, GL_DYNAMIC_STORAGE_BIT);
glCreateVertexArrays(1, &VAO);
GLint vbuf_index = 0;
glVertexArrayVertexBuffer(VAO, vbuf_index, VBO, 0, sizeof(struct Vertex2D));
GLint a_pos = 0;
glVertexArrayAttribFormat(VAO, a_pos, 2, GL_FLOAT, GL_FALSE, offsetof(struct Vertex2D, pos));
glVertexArrayAttribBinding(VAO, a_pos, vbuf_index);
glEnableVertexArrayAttrib(VAO, a_pos);
GLint a_tex = 1;
glVertexArrayAttribFormat(VAO, a_tex, 2, GL_FLOAT, GL_FALSE, offsetof(struct Vertex2D, tex));
glVertexArrayAttribBinding(VAO, a_tex, vbuf_index);
glEnableVertexArrayAttrib(VAO, a_tex);
GLint a_color = 2;
glVertexArrayAttribFormat(VAO, a_color, 4, GL_UNSIGNED_BYTE, GL_FALSE, offsetof(struct Vertex2D, color));
glVertexArrayAttribBinding(VAO, a_color, vbuf_index);
glEnableVertexArrayAttrib(VAO, a_color);
char *glsl_vshader = R"==(
#version 450 core
layout(location=0) uniform vec2 U_InvHalfScreenSize;
layout(location=0) in vec2 VPos;
layout(location=1) in vec2 VTex;
layout(location=2) in vec4 VColor;
out gl_PerVertex { vec4 gl_Position; }; // required because of ARB_separate_shader_objects
out vec2 FUV;
out vec4 FColor;
void main() {
vec2 pos = VPos * U_InvHalfScreenSize;
pos.y = 2 - pos.y; // invert y axis
pos -= vec2(1, 1); // convert to 0,1 range
gl_Position = vec4(pos, 0, 1);
FUV = VTex;
FColor = VColor / 255.0;
}
)==";
char *glsl_fshader = R"==(
#version 450 core
in vec2 FUV;
in vec4 FColor;
layout (binding=0) uniform sampler2D S_Texture;
layout (location=0) out vec4 OutColor;
void main() {
vec4 c = FColor;
c.a *= texture(S_Texture, FUV).r;
OutColor = c;
}
)==";
Shader2D = CreateShader(glsl_vshader, glsl_fshader);
}
Shader CreateShader(char *glsl_vshader, char *glsl_fshader) {
Shader result = {};
result.vshader = glCreateShaderProgramv(GL_VERTEX_SHADER, 1, &glsl_vshader);
result.fshader = glCreateShaderProgramv(GL_FRAGMENT_SHADER, 1, &glsl_fshader);
GLint linked;
glGetProgramiv(result.vshader, GL_LINK_STATUS, &linked);
if (!linked) {
char message[1024];
glGetProgramInfoLog(result.vshader, sizeof(message), NULL, message);
SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Failed to create vertex shader!", message, NULL);
}
glGetProgramiv(result.fshader, GL_LINK_STATUS, &linked);
if (!linked) {
char message[1024];
glGetProgramInfoLog(result.fshader, sizeof(message), NULL, message);
SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Failed to create fragment shader!", message, NULL);
}
glGenProgramPipelines(1, &result.pipeline);
glUseProgramStages(result.pipeline, GL_VERTEX_SHADER_BIT, result.vshader);
glUseProgramStages(result.pipeline, GL_FRAGMENT_SHADER_BIT, result.fshader);
return result;
}
#define SLL_QUEUE_ADD_MOD(f, l, n, next) \
do { \
(n)->next = 0; \
if ((f) == 0) { \
(f) = (l) = (n); \
} else { \
(l) = (l)->next = (n); \
} \
} while (0)
#define SLL_QUEUE_ADD(f, l, n) SLL_QUEUE_ADD_MOD(f, l, n, next)
Vertex2D *AllocVertex2D(Allocator allocator, VertexList2D *list, int count) {
VertexNode2D *node = list->last;
if (node == 0 || node->count + count > Lengthof(node->vertices)) {
node = AllocType(allocator, VertexNode2D);
SLL_QUEUE_ADD(list->first, list->last, node);
}
TotalVertexCount += count;
Vertex2D *result = node->vertices + node->count;
node->count += count;
return result;
}
void PushVertex2D(Allocator allocator, VertexList2D *list, Vertex2D *vertices, int count) {
Vertex2D *result = AllocVertex2D(allocator, list, count);
for (int i = 0; i < count; i += 1) result[i] = vertices[i];
}
void PushQuad2D(Allocator arena, VertexList2D *list, Rect2 rect, Rect2 tex, Color color, float rotation = 0.f, Vec2 rotation_point = {}) {
Vertex2D *v = AllocVertex2D(arena, list, 6);
v[0] = {
{rect.min.x, rect.max.y},
{ tex.min.x, tex.max.y},
color
};
v[1] = {
{rect.max.x, rect.max.y},
{ tex.max.x, tex.max.y},
color
};
v[2] = {
{rect.min.x, rect.min.y},
{ tex.min.x, tex.min.y},
color
};
v[3] = {
{rect.min.x, rect.min.y},
{ tex.min.x, tex.min.y},
color
};
v[4] = {
{rect.max.x, rect.max.y},
{ tex.max.x, tex.max.y},
color
};
v[5] = {
{rect.max.x, rect.min.y},
{ tex.max.x, tex.min.y},
color
};
if (rotation != 0.f) {
float s = sinf(rotation);
float c = cosf(rotation);
for (int i = 0; i < 6; i += 1) {
v[i].pos -= rotation_point;
v[i].pos = {v[i].pos.x * c + v[i].pos.y * (-s), v[i].pos.x * s + v[i].pos.y * c};
v[i].pos += rotation_point;
}
}
}
void DrawRect(Rect2 rect, Color color) {
PushQuad2D(RenderArena, &Vertices, rect, MainFont.white_texture_bounding_box, color);
}
Vec2 DrawString(Font *font, String16 string, Vec2 pos, Color color, bool draw = true) {
pos.y += font->ascent;
Vec2 original_pos = pos;
For(string) {
Glyph *g = GetGlyph(font, it);
Rect2 rect = Rect2FromSize(pos + g->offset, g->size);
if (draw && it != '\n' && it != ' ' && it != '\t') {
PushQuad2D(RenderArena, &Vertices, rect, g->atlas_bounding_box, color);
}
pos.x += g->xadvance;
}
Vec2 result = {pos.x - original_pos.x, font->size};
return result;
}
Vec2 GetStringSize(Font *font, String16 string, Vec2 pos, Color color) {
return DrawString(font, string, pos, color, false);
}
Int GetCharSpacing(Font *font) {
Glyph *g = GetGlyph(font, '_');
if (g->xadvance) return (Int)g->xadvance;
return (Int)g->size.x;
}
void BeginScissor(Rect2 rect) {
glScissor((GLint)rect.min.x, (GLint)rect.min.y, (GLsizei)(rect.max.x - rect.min.x), (GLsizei)(rect.max.y - rect.min.y));
}
void EndScissor() {
glScissor(0, 0, (GLsizei)WindowSize.x, (GLsizei)WindowSize.y);
}
Rect2 GetScreenRectF() {
Rect2 result = {0, 0, WindowSize.x, WindowSize.y};
return result;
}
Rect2I GetScreenRectI() {
Rect2I result = {0, 0, (Int)WindowSize.x, (Int)WindowSize.y};
return result;
}