orca/samples/glesTriangle/src/main.c

114 lines
2.5 KiB
C

#include <keys.h>
#include <math.h>
#include <orca.h>
vec2 frameSize = {100, 100};
mg_surface surface;
unsigned int program;
const char* vshaderSource =
"attribute vec4 vPosition;\n"
"uniform mat4 transform;\n"
"void main()\n"
"{\n"
" gl_Position = transform*vPosition;\n"
"}\n";
const char* fshaderSource =
"precision mediump float;\n"
"void main()\n"
"{\n"
" gl_FragColor = 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)
{
log_info("gl error");
}
}
char* ORCA_IMPORT(orca_mem_grow)(u64 size);
ORCA_EXPORT void OnInit(void)
{
surface = mg_surface_gles();
mg_surface_prepare(surface);
const char* extensions = (const char*)glGetString(GL_EXTENSIONS);
log_info("GLES extensions: %s\n", extensions);
int extensionCount = 0;
glGetIntegerv(GL_NUM_EXTENSIONS, &extensionCount);
for(int i=0; i<extensionCount; i++)
{
const char* extension = (const char*)glGetStringi(GL_EXTENSIONS, i);
log_info("GLES extension %i: %s\n", i, extension);
}
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);
glUseProgram(program);
GLfloat vertices[] = {
-0.866/2, -0.5/2, 0, 0.866/2, -0.5/2, 0, 0, 0.5, 0};
GLuint buffer;
glGenBuffers(1, &buffer);
glBindBuffer(GL_ARRAY_BUFFER, buffer);
glBufferData(GL_ARRAY_BUFFER, 9*sizeof(GLfloat), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
}
ORCA_EXPORT void OnFrameResize(u32 width, u32 height)
{
log_info("frame resize %u, %u", width, height);
frameSize.x = width;
frameSize.y = height;
}
ORCA_EXPORT void OnFrameRefresh(void)
{
f32 aspect = frameSize.x/frameSize.y;
mg_surface_prepare(surface);
glClearColor(0, 1, 1, 1);
glClear(GL_COLOR_BUFFER_BIT);
static float alpha = 0;
glViewport(0, 0, frameSize.x * 2, frameSize.y * 2);
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);
glDrawArrays(GL_TRIANGLES, 0, 3);
mg_surface_present(surface);
}