orca/sketches/triangleGL/main.c

174 lines
4.2 KiB
C

/*************************************************************************
*
* Orca
* Copyright 2023 Martin Fouilleul and the Orca project contributors
* See LICENSE.txt for licensing information
*
**************************************************************************/
#include <stdio.h>
#include <string.h>
#define _USE_MATH_DEFINES //NOTE: necessary for MSVC
#include <math.h>
#define OC_INCLUDE_GL_API
#include "orca.h"
unsigned int program;
const char* vshaderSource =
"#version 430\n"
"in vec4 vPosition;\n"
"uniform mat4 transform;\n"
"void main()\n"
"{\n"
" gl_Position = transform*vPosition;\n"
"}\n";
const char* fshaderSource =
"#version 430\n"
"precision mediump float;\n"
"layout(location = 0) out vec4 diffuse;"
"void main()\n"
"{\n"
" diffuse = vec4(1.0, 0.0, 0.0, 1.0);\n"
"}\n";
void compile_shader(GLuint shader, const char* source)
{
glShaderSource(shader, 1, &source, 0);
glCompileShader(shader);
int err = glGetError();
if(err)
{
oc_log_error("gl error: %i\n", err);
}
int status = 0;
glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
if(!status)
{
char buffer[256];
int size = 0;
glGetShaderInfoLog(shader, 256, &size, buffer);
oc_log_error("shader error: %.*s\n", size, buffer);
}
}
int main()
{
oc_init();
oc_rect rect = { .x = 100, .y = 100, .w = 800, .h = 600 };
oc_window window = oc_window_create(rect, OC_STR8("test"), 0);
//NOTE: create surface
oc_surface surface = oc_surface_create_for_window(window, OC_GL);
if(oc_surface_is_nil(surface))
{
#if OC_PLATFORM_MACOS
OC_ABORT("Desktop OpenGL surface is not implemented yet on macOS\n");
#else
OC_ABORT("Couldn't create GL surface\n");
#endif
}
//NOTE: init shader and gl state
oc_surface_select(surface);
GLuint vao;
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
GLuint vertexBuffer;
glGenBuffers(1, &vertexBuffer);
GLfloat vertices[] = {
-0.866 / 2, -0.5 / 2, 0, 0.866 / 2, -0.5 / 2, 0, 0, 0.5, 0
};
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
unsigned int vshader = glCreateShader(GL_VERTEX_SHADER);
unsigned int fshader = glCreateShader(GL_FRAGMENT_SHADER);
program = glCreateProgram();
compile_shader(vshader, vshaderSource);
compile_shader(fshader, fshaderSource);
glAttachShader(program, vshader);
glAttachShader(program, fshader);
glLinkProgram(program);
int status = 0;
glGetProgramiv(program, GL_LINK_STATUS, &status);
if(!status)
{
char buffer[256];
int size = 0;
glGetProgramInfoLog(program, 256, &size, buffer);
oc_log_error("link error: %.*s\n", size, buffer);
}
glUseProgram(program);
oc_window_bring_to_front(window);
// oc_window_focus(window);
while(!oc_should_quit())
{
oc_arena_scope* scratch = oc_scratch_begin();
oc_pump_events(0);
oc_event* event = 0;
while((event = oc_next_event(scratch.arena)) != 0)
{
switch(event->type)
{
case OC_EVENT_WINDOW_CLOSE:
{
oc_request_quit();
}
break;
default:
break;
}
}
oc_surface_select(surface);
glClearColor(0.3, 0.3, 1, 1);
glClear(GL_COLOR_BUFFER_BIT);
static float alpha = 0;
//f32 aspect = frameSize.x/frameSize.y;
f32 aspect = 800 / (f32)600;
GLfloat matrix[] = { cosf(alpha) / aspect, sinf(alpha), 0, 0,
-sinf(alpha) / aspect, cosf(alpha), 0, 0,
0, 0, 1, 0,
0, 0, 0, 1 };
alpha += 2 * M_PI / 120;
glUniformMatrix4fv(0, 1, false, matrix);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
glDrawArrays(GL_TRIANGLES, 0, 3);
oc_surface_present(surface);
oc_scratch_end(scratch);
}
oc_terminate();
return (0);
}