/*
* Mr. 4th Dimention - Allen Webster
*
* 10.11.2017
*
* OpenGL render implementation
*
*/
// TOP
// TODO(allen): If we don't actually need this then burn down 4ed_opengl_funcs.h
// Declare function types and function pointers
//#define GL_FUNC(N,R,P) typedef R (N##_Function) P; N##_Function *P = 0;
//#include "4ed_opengl_funcs.h"
#include "4ed_opengl_defines.h"
// OpenGL 2.1 implementation
internal GLuint
private_texture_initialize(GLint tex_width, GLint tex_height, u32 *pixels){
GLuint tex;
glGenTextures(1, &tex);
glBindTexture(GL_TEXTURE_2D, tex);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, tex_width, tex_height, 0, GL_ALPHA, GL_UNSIGNED_INT, pixels);
return(tex);
}
inline void
private_draw_bind_texture(Render_Target *t, i32 texid){
if (t->bound_texture != texid){
glBindTexture(GL_TEXTURE_2D, texid);
t->bound_texture = texid;
}
}
inline void
private_draw_set_color(Render_Target *t, u32 color){
if (t->color != color){
t->color = color;
Vec4 c = unpack_color4(color);
glColor4f(c.r, c.g, c.b, c.a);
}
}
internal void
interpret_render_buffer(Render_Target *t, Partition *growable_scratch){
local_persist b32 first_opengl_call = true;
if (first_opengl_call){
first_opengl_call = false;
char *vendor = (char *)glGetString(GL_VENDOR);
char *renderer = (char *)glGetString(GL_RENDERER);
char *version = (char *)glGetString(GL_VERSION);
LOGF("GL_VENDOR: %s\n", vendor);
LOGF("GL_RENDERER: %s\n", renderer);
LOGF("GL_VERSION: %s\n", version);
// TODO(allen): Get this up and running for dev mode again.
#if (defined(BUILD_X64) && 0) || (defined(BUILD_X86) && 0)
// NOTE(casey): This slows down GL but puts error messages to
// the debug console immediately whenever you do something wrong
void CALL_CONVENTION gl_dbg(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const char *message, const void *userParam);
glDebugMessageCallback_type *glDebugMessageCallback =
(glDebugMessageCallback_type *)win32_load_gl_always("glDebugMessageCallback", module);
glDebugMessageControl_type *glDebugMessageControl =
(glDebugMessageControl_type *)win32_load_gl_always("glDebugMessageControl", module);
if(glDebugMessageCallback != 0 && glDebugMessageControl != 0)
{
glDebugMessageCallback(opengl_debug_callback, 0);
glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, 0, GL_TRUE);
glEnable(GL_DEBUG_OUTPUT);
glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
}
#endif
glEnable(GL_TEXTURE_2D);
glEnable(GL_SCISSOR_TEST);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
i32 width = t->width;
i32 height = t->height;
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, width, height, 0, -1, 1);
glScissor(0, 0, width, height);
glClearColor(1.f, 0.f, 1.f, 1.f);
glClear(GL_COLOR_BUFFER_BIT);
glBindTexture(GL_TEXTURE_2D, 0);
t->bound_texture = 0;
glColor4f(0.f, 0.f, 0.f, 0.f);
t->color = 0;
for (Render_Free_Texture *free_texture = t->free_texture_first;
free_texture != 0;
free_texture = free_texture->next){
glDeleteTextures(1, &free_texture->tex_id);
}
sll_clear(t->free_texture_first, t->free_texture_last);
u8 *start = (u8*)t->buffer.base;
u8 *end = (u8*)t->buffer.base + t->buffer.pos;
Render_Command_Header *header = 0;
for (u8 *p = start; p < end; p += header->size){
header = (Render_Command_Header*)p;
i32 type = header->type;
switch (type){
case RenCom_Rectangle:
{
Render_Command_Rectangle *rectangle = (Render_Command_Rectangle*)header;
f32_Rect r = rectangle->rect;
private_draw_set_color(t, rectangle->color);
private_draw_bind_texture(t, 0);
glBegin(GL_QUADS);
{
glVertex2f(r.x0, r.y0);
glVertex2f(r.x0, r.y1);
glVertex2f(r.x1, r.y1);
glVertex2f(r.x1, r.y0);
}
glEnd();
}break;
case RenCom_Outline:
{
Render_Command_Rectangle *rectangle = (Render_Command_Rectangle*)header;
f32_Rect r = get_inner_rect(rectangle->rect, .5f);
private_draw_set_color(t, rectangle->color);
private_draw_bind_texture(t, 0);
glBegin(GL_LINE_STRIP);
{
glVertex2f(r.x0, r.y0);
glVertex2f(r.x1, r.y0);
glVertex2f(r.x1, r.y1);
glVertex2f(r.x0, r.y1);
glVertex2f(r.x0, r.y0);
}
glEnd();
}break;
case RenCom_Glyph:
{
Render_Command_Glyph *glyph = (Render_Command_Glyph*)header;
Font_Pointers font = system_font_get_pointers_by_id(glyph->font_id);
if (!font.valid){
break;
}
u32 codepoint = glyph->codepoint;
u32 page_number = codepoint/GLYPHS_PER_PAGE;
Glyph_Page *page = font_cached_get_page(font.pages, page_number);
if (page == 0){
break;
}
if (!page->has_gpu_setup){
Temp_Memory temp = begin_temp_memory(growable_scratch);
i32 tex_width = 0;
i32 tex_height = 0;
u32 *pixels = font_load_page_pixels(growable_scratch, font.settings, page, page_number, &tex_width, &tex_height);
page->has_gpu_setup = true;
page->gpu_tex = private_texture_initialize(tex_width, tex_height, pixels);
end_temp_memory(temp);
}
if (page->gpu_tex == 0){
break;
}
u32 glyph_index = codepoint%GLYPHS_PER_PAGE;
Glyph_Bounds bounds = page->glyphs[glyph_index];
GLuint tex = page->gpu_tex;
i32 tex_width = page->tex_width;
i32 tex_height = page->tex_height;
f32 x = glyph->pos.x;
f32 y = glyph->pos.y;
f32_Rect xy = {0};
xy.x0 = x + bounds.xoff;
xy.y0 = y + bounds.yoff;
xy.x1 = x + bounds.xoff2;
xy.y1 = y + bounds.yoff2;
// TODO(allen): Why aren't these baked in???
f32 unit_u = 1.f/tex_width;
f32 unit_v = 1.f/tex_height;
f32_Rect uv = {0};
uv.x0 = bounds.x0*unit_u;
uv.y0 = bounds.y0*unit_v;
uv.x1 = bounds.x1*unit_u;
uv.y1 = bounds.y1*unit_v;
private_draw_set_color(t, glyph->color);
private_draw_bind_texture(t, tex);
glBegin(GL_QUADS);
{
glTexCoord2f(uv.x0, uv.y1); glVertex2f(xy.x0, xy.y1);
glTexCoord2f(uv.x1, uv.y1); glVertex2f(xy.x1, xy.y1);
glTexCoord2f(uv.x1, uv.y0); glVertex2f(xy.x1, xy.y0);
glTexCoord2f(uv.x0, uv.y0); glVertex2f(xy.x0, xy.y0);
}
glEnd();
if (codepoint != ' ' && font.settings->parameters.underline){
glDisable(GL_TEXTURE_2D);
f32 x0 = x;
f32 x1 = x + page->advance[glyph_index];
f32 yoff1 = y + font.metrics->underline_yoff1;
f32 yoff2 = y + font.metrics->underline_yoff2;
glBegin(GL_QUADS);
{
glVertex2f(x0, yoff1);
glVertex2f(x1, yoff1);
glVertex2f(x1, yoff2);
glVertex2f(x0, yoff2);
}
glEnd();
glEnable(GL_TEXTURE_2D);
}
}break;
case RenCom_ChangeClip:
{
Render_Command_Change_Clip *clip = (Render_Command_Change_Clip*)header;
i32_Rect box = clip->box;
glScissor(box.x0, height - box.y1, box.x1 - box.x0, box.y1 - box.y0);
}break;
}
}
glFlush();
}
// BOTTOM