GLuint modelEngine::linkShaderProgram(int shaderIndex)
{
GLuint programHandle = glCreateProgram();
glAttachShader(programHandle, shaders[shaderIndex].vertexShader);
glAttachShader(programHandle, shaders[shaderIndex].fragmentShader);
glLinkProgram(programHandle);
showprogramlog(programHandle);
shaders[shaderIndex].program = programHandle;
// Get and store attributes
GLint attribLocation = 0;
attribLocation = glGetAttribLocation(programHandle, "Position");
if(attribLocation != GL_INVALID_OPERATION)
{
shaders[shaderIndex].Position = attribLocation;
}
attribLocation = glGetAttribLocation(programHandle, "SourceColor");
if(attribLocation != GL_INVALID_OPERATION)
{
shaders[shaderIndex].SourceColor = attribLocation;
}
// Enable attribute
glVertexAttribPointer(shaders[shaderIndex].Position, 4, GL_FLOAT, 0, 16, 0);
glEnableVertexAttribArray(shaders[shaderIndex].Position);
numShaders++;
return programHandle;
}
static void init_shaders(CUBE_STATE_T *state)
{
static const GLfloat vertex_data[] = {
-1.0,-1.0,1.0,
1.0,-1.0,1.0,
1.0,1.0,1.0,
-1.0,1.0,1.0,
};
const GLchar *vshader_source =
"attribute vec4 vertex;"
"varying vec2 tcoord;"
"void main(void) {"
" vec4 pos = vertex;"
" gl_Position = pos;"
" tcoord = vertex.xy*0.5+0.5;"
"}";
#if 0
//Mandelbrot
const GLchar *mandelbrot_fshader_source =
"uniform vec4 color;"
"uniform vec2 scale;"
"uniform vec2 centre;"
"varying vec2 tcoord;"
"void main(void) {"
" float intensity;"
" vec4 color2;"
" float cr=(gl_FragCoord.x-centre.x)*scale.x;"
" float ci=(gl_FragCoord.y-centre.y)*scale.y;"
" float ar=cr;"
" float ai=ci;"
" float tr,ti;"
" float col=0.0;"
" float p=0.0;"
" int i=0;"
" for(int i2=1;i2<16;i2++)"
" {"
" tr=ar*ar-ai*ai+cr;"
" ti=2.0*ar*ai+ci;"
" p=tr*tr+ti*ti;"
" ar=tr;"
" ai=ti;"
" if (p>16.0)"
" {"
" i=i2;"
" break;"
" }"
" }"
" color2 = vec4(float(i)*0.0625,0,0,1);"
" gl_FragColor = color2;"
"}";
// Julia
const GLchar *julia_fshader_source =
"uniform vec4 color;"
"uniform vec2 scale;"
"uniform vec2 centre;"
"uniform vec2 offset;"
"varying vec2 tcoord;"
"uniform sampler2D tex;"
"void main(void) {"
" float intensity;"
" vec4 color2;"
" float ar=(gl_FragCoord.x-centre.x)*scale.x;"
" float ai=(gl_FragCoord.y-centre.y)*scale.y;"
" float cr=(offset.x-centre.x)*scale.x;"
" float ci=(offset.y-centre.y)*scale.y;"
" float tr,ti;"
" float col=0.0;"
" float p=0.0;"
" int i=0;"
" vec2 t2;"
" t2.x=tcoord.x+(offset.x-centre.x)*(0.5/centre.y);"
" t2.y=tcoord.y+(offset.y-centre.y)*(0.5/centre.x);"
" for(int i2=1;i2<16;i2++)"
" {"
" tr=ar*ar-ai*ai+cr;"
" ti=2.0*ar*ai+ci;"
" p=tr*tr+ti*ti;"
" ar=tr;"
" ai=ti;"
" if (p>16.0)"
" {"
" i=i2;"
" break;"
" }"
" }"
" color2 = vec4(0,float(i)*0.0625,0,1);"
" color2 = color2+texture2D(tex,t2);"
" gl_FragColor = color2;"
"}";
state->vshader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(state->vshader, 1, &vshader_source, 0);
glCompileShader(state->vshader);
check();
if (state->verbose)
showlog(state->vshader);
state->fshader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(state->fshader, 1, &julia_fshader_source, 0);
glCompileShader(state->fshader);
check();
if (state->verbose)
showlog(state->fshader);
state->mshader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(state->mshader, 1, &mandelbrot_fshader_source, 0);
glCompileShader(state->mshader);
check();
if (state->verbose)
showlog(state->mshader);
// julia
state->program = glCreateProgram();
glAttachShader(state->program, state->vshader);
glAttachShader(state->program, state->fshader);
glLinkProgram(state->program);
check();
if (state->verbose)
showprogramlog(state->program);
state->attr_vertex = glGetAttribLocation(state->program, "vertex");
state->unif_color = glGetUniformLocation(state->program, "color");
state->unif_scale = glGetUniformLocation(state->program, "scale");
state->unif_offset = glGetUniformLocation(state->program, "offset");
state->unif_tex = glGetUniformLocation(state->program, "tex");
state->unif_centre = glGetUniformLocation(state->program, "centre");
// mandelbrot
state->program2 = glCreateProgram();
glAttachShader(state->program2, state->vshader);
glAttachShader(state->program2, state->mshader);
glLinkProgram(state->program2);
check();
if (state->verbose)
showprogramlog(state->program2);
state->attr_vertex2 = glGetAttribLocation(state->program2, "vertex");
state->unif_scale2 = glGetUniformLocation(state->program2, "scale");
state->unif_offset2 = glGetUniformLocation(state->program2, "offset");
state->unif_centre2 = glGetUniformLocation(state->program2, "centre");
check();
#endif
glClearColor ( 0.0, 1.0, 1.0, 1.0 );
glGenBuffers(1, &state->buf);
check();
// Prepare a texture image
glGenTextures(1, &state->tex);
check();
glBindTexture(GL_TEXTURE_2D,state->tex);
check();
// glActiveTexture(0)
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,state->screen_width,state->screen_height,0,GL_RGB,GL_UNSIGNED_SHORT_5_6_5,0);
check();
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
check();
// Prepare a framebuffer for rendering
glGenFramebuffers(1,&state->tex_fb);
check();
glBindFramebuffer(GL_FRAMEBUFFER,state->tex_fb);
check();
glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,state->tex,0);
check();
glBindFramebuffer(GL_FRAMEBUFFER,0);
check();
// Prepare viewport
glViewport ( 0, 0, state->screen_width, state->screen_height );
check();
// Upload vertex data to a buffer
glBindBuffer(GL_ARRAY_BUFFER, state->buf);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data),
vertex_data, GL_STATIC_DRAW);
glVertexAttribPointer(state->attr_vertex, 3, GL_FLOAT, 0, 12, 0);
glEnableVertexAttribArray(state->attr_vertex);
check();
}
int main ()
{
int terminate = 1;
bcm_host_init();
// Clear application state
memset( state, 0, sizeof( *state ) );
// Start OGLES
init_ogl(state);
//init_shaders(state);
char vShaderSource[] =
"attribute vec4 vPosition; \n"
"uniform vec4 offset; \n"
"void main() \n"
"{ \n"
" vec4 nPosition = (vPosition*vec4(0.25, 0.25, 0.25, 1.0))+offset; \n"
" gl_Position = nPosition; \n"
"} \n";
//everything is black
char fShaderSource[] =
"precision mediump float; \n"
"void main() \n"
"{ \n"
" gl_FragColor = vec4(1.0, 1.0, 1.0, 0.5); \n"
"} \n";
GLuint vshader = LoadShader(vShaderSource, GL_VERTEX_SHADER);
GLuint fshader = LoadShader(fShaderSource, GL_FRAGMENT_SHADER);
GLuint programObj = glCreateProgram();
GLint linked;
check();
assert(programObj != 0);
glAttachShader(programObj, vshader);
glAttachShader(programObj, fshader);
glBindAttribLocation(programObj, 0, "vPosition");
check();
glLinkProgram(programObj);
check();
glGetProgramiv(programObj, GL_LINK_STATUS, &linked);
if(linked != GL_TRUE)
{
showprogramlog(programObj);
glDeleteProgram(programObj);
return -1;
}
GLint offset = glGetUniformLocation(programObj, "offset");
check();
GLfloat vVertices[] =
{ 0.f, -0.25f, 0.0f,
0.5f, 0.25f, 0.0f,
0.75f, -0.25f, 0.0f
};
glViewport(0,0, state->screen_width, state->screen_height);
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(programObj);
GLfloat offet_vector[] = { 0.5f, 0.0f, 0.0f, 0.0f };
glUniform4fv(offset, 4, offet_vector);
glVertexAttribPointer(0,3, GL_FLOAT, GL_FALSE, 0, vVertices);
glEnableVertexAttribArray(0);
glDrawArrays(GL_TRIANGLES, 0, 3);
glDisableVertexAttribArray(0);
GLfloat square[] =
{
-1.00f, -1.00f, 0.0f, // Bottom Left
1.00f, -1.00f, 0.0f, // Bottom Right
-1.00f, 1.00f, 0.0f, // Top Left
1.00f, 1.00f, 0.0f //Top Right
};
GLfloat sqoffet_vector[] = { -0.5f, 0.0f, 0.0f, 0.0f };
glUniform4fv(offset, 4, sqoffet_vector);
//glUniform1f(offset, -0.5);
glVertexAttribPointer(0,3, GL_FLOAT, GL_FALSE, 0, square);
glEnableVertexAttribArray(0);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glDisableVertexAttribArray(0);
eglSwapBuffers(state->display, state->surface);
getchar();
while (!terminate)
{
}
return 0;
}
static void init_shaders(CUBE_STATE_T *state)
{
static const GLfloat vertex_data[] = {
-1.0,-1.0,1.0,1.0,
1.0,-1.0,1.0,1.0,
1.0,1.0,1.0,1.0,
-1.0,1.0,1.0,1.0
};
const GLchar *vshader_source =
"attribute vec4 vertex;"
"void main(void) {"
" vec4 pos = vertex;"
" gl_Position = pos;"
"}";
const GLchar *fshader_source =
"void main(void) {"
" gl_FragColor = vec4(0,1,0,1);"
"}";
state->vshader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(state->vshader, 1, &vshader_source, 0);
glCompileShader(state->vshader);
check();
if (state->verbose)
showlog(state->vshader);
state->fshader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(state->fshader, 1, &fshader_source, 0);
glCompileShader(state->fshader);
check();
if (state->verbose)
showlog(state->fshader);
state->program = glCreateProgram();
glAttachShader(state->program, state->vshader);
glAttachShader(state->program, state->fshader);
glLinkProgram(state->program);
check();
if (state->verbose)
showprogramlog(state->program);
state->attr_vertex = glGetAttribLocation(state->program, "vertex");
#if 0
state->unif_color = glGetUniformLocation(state->program, "color");
state->unif_scale = glGetUniformLocation(state->program, "scale");
state->unif_offset = glGetUniformLocation(state->program, "offset");
state->unif_tex = glGetUniformLocation(state->program, "tex");
state->unif_centre = glGetUniformLocation(state->program, "centre");
#endif
check();
glClearColor ( 0.0, 1.0, 1.0, 1.0 );
glGenBuffers(1, &state->buf);
check();
// Prepare a texture image
glGenTextures(1, &state->tex);
check();
glBindTexture(GL_TEXTURE_2D,state->tex);
check();
// glActiveTexture(0)
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,state->screen_width,state->screen_height,0,GL_RGB,GL_UNSIGNED_SHORT_5_6_5,0);
check();
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
check();
// Prepare a framebuffer for rendering
glGenFramebuffers(1,&state->tex_fb);
check();
glBindFramebuffer(GL_FRAMEBUFFER,state->tex_fb);
check();
glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,state->tex,0);
check();
glBindFramebuffer(GL_FRAMEBUFFER,0);
check();
// Prepare viewport
glViewport ( 0, 0, state->screen_width, state->screen_height );
check();
// Upload vertex data to a buffer
glBindBuffer(GL_ARRAY_BUFFER, state->buf);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data),
vertex_data, GL_STATIC_DRAW);
glVertexAttribPointer(state->attr_vertex, 4, GL_FLOAT, 0, 16, 0);
glEnableVertexAttribArray(state->attr_vertex);
check();
}
