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PoisonousJohn/Fragment.glsl

Forked from anonymous/Fragment.glsl
Created December 18, 2012 14:01
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Fragment.glsl
varying lowp vec4 DestinationColor; // 1
void main(void) { // 2
gl_FragColor = DestinationColor; // 3
}
Raw
gistfile1.m
//
// Created by JohnPoison <truefiresnake@gmail.com> on 10/24/12.
#import <QuartzCore/QuartzCore.h>
#import "OpenGLView.h"
#import "CC3GLMatrix.h"
@implementation OpenGLView {
}
//typedef struct {
// float Position[3];
// float Color[4];
//} Vertex;
//const Vertex Vertices[] = {
// {{1, -1, -7}, {1, 0, 0, 1}},
// {{1, 1, -7}, {0, 1, 0, 1}},
// {{-1, 1, -7}, {0, 0, 1, 1}},
// {{-1, -1, -7}, {0, 0, 0, 1}}
//};
const GLubyte Indices[] = {
0, 1, 2,
2, 3, 0
};
+ (Class)layerClass {
return [CAEAGLLayer class];
}
- (void)setupLayer {
_eaglLayer = (CAEAGLLayer*) self.layer;
_eaglLayer.opaque = YES;
}
- (void)setupContext {
EAGLRenderingAPI api = kEAGLRenderingAPIOpenGLES2;
_context = [[EAGLContext alloc] initWithAPI:api];
if (!_context) {
NSLog(@"Failed to initialize OpenGLES 2.0 context");
exit(1);
}
if (![EAGLContext setCurrentContext:_context]) {
NSLog(@"Failed to set current OpenGL context");
exit(1);
}
}
- (void)setupRenderBuffer {
glGenRenderbuffers(1, &_colorRenderBuffer);
glBindRenderbuffer(GL_RENDERBUFFER, _colorRenderBuffer);
[_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:_eaglLayer];
}
- (void)setupFrameBuffer {
GLuint framebuffer;
glGenFramebuffers(1, &framebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_RENDERBUFFER, _colorRenderBuffer);
}
- (void) render {
glClearColor(0, 104.0/255.0, 55.0/255.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
CC3GLMatrix *projection = [CC3GLMatrix matrix];
float h = 4.0f * self.frame.size.height / self.frame.size.width;
[projection populateFromFrustumLeft:-2 andRight:2 andBottom:-h/2 andTop:h/2 andNear:4 andFar:10];
glUniformMatrix4fv(_projectionUniform, 1, 0, projection.glMatrix);
// 1
glViewport(0, 0, self.frame.size.width, self.frame.size.height);
// 2
// glVertexAttribPointer(_positionSlot, 3, GL_FLOAT, GL_FALSE,
// sizeof(Vertex), 0);
glVertexAttribPointer(_positionSlot, 3, GL_FLOAT, GL_FALSE,
sizeof(float), 0);
// glVertexAttribPointer(_colorSlot, 4, GL_FLOAT, GL_FALSE,
// sizeof(Vertex), (GLvoid*) (sizeof(float) * 3));
float color[4] = {1.0,1.0,1.0, 1.0};
// float color[4] = {0,0,0,1};
glUniform4fv(_colorSlot, 1, color);
// glUniform4f(_colorSlot, 1, 1, 1, 1);
// 3
// glDrawElements(GL_LINE_STRIP, sizeof(Indices)/sizeof(Indices[0]),GL_UNSIGNED_BYTE, 0);
glDrawArrays(GL_LINE_STRIP, 0, sizeof(verticesCount));
[_context presentRenderbuffer:GL_RENDERBUFFER];
}
- (GLuint)compileShader:(NSString*)shaderName withType:(GLenum)shaderType {
NSLog(@"Compiling shader %@", shaderName);
// 1
NSString* shaderPath = [[NSBundle mainBundle] pathForResource:shaderName
ofType:@"glsl"];
NSError* error;
NSString* shaderString = [NSString stringWithContentsOfFile:shaderPath
encoding:NSUTF8StringEncoding error:&error];
if (!shaderString) {
NSLog(@"Error loading shader: %@", error.localizedDescription);
exit(1);
}
// 2
GLuint shaderHandle = glCreateShader(shaderType);
// 3
const char * shaderStringUTF8 = [shaderString UTF8String];
int shaderStringLength = [shaderString length];
glShaderSource(shaderHandle, 1, &shaderStringUTF8, &shaderStringLength);
// 4
glCompileShader(shaderHandle);
// 5
GLint compileSuccess;
glGetShaderiv(shaderHandle, GL_COMPILE_STATUS, &compileSuccess);
if (compileSuccess == GL_FALSE) {
GLchar messages[256];
glGetShaderInfoLog(shaderHandle, sizeof(messages), 0, &messages[0]);
NSString *messageString = [NSString stringWithUTF8String:messages];
NSLog(@"%@", messageString);
exit(1);
}
return shaderHandle;
}
- (void)dealloc {
free (cylinderVertices);
free (drawIndexes);
}
- (void)compileShaders {
NSLog(@"Compiling shaders");
// 1
GLuint vertexShader = [self compileShader:@"SimpleVertex"
withType:GL_VERTEX_SHADER];
GLuint fragmentShader = [self compileShader:@"SimpleFragment"
withType:GL_FRAGMENT_SHADER];
// 2
GLuint programHandle = glCreateProgram();
glAttachShader(programHandle, vertexShader);
glAttachShader(programHandle, fragmentShader);
glLinkProgram(programHandle);
// 3
GLint linkSuccess;
glGetProgramiv(programHandle, GL_LINK_STATUS, &linkSuccess);
if (linkSuccess == GL_FALSE) {
GLchar messages[256];
glGetProgramInfoLog(programHandle, sizeof(messages), 0, &messages[0]);
NSString *messageString = [NSString stringWithUTF8String:messages];
NSLog(@"shaders compile error: %@", messageString);
exit(1);
}
// 4
glUseProgram(programHandle);
// 5
_positionSlot = glGetAttribLocation(programHandle, "Position");
_colorSlot = glGetUniformLocation(programHandle, "SourceColor");
glEnableVertexAttribArray(_positionSlot);
// glEnableVertexAttribArray(_colorSlot);
_projectionUniform = glGetUniformLocation(programHandle, "Projection");
}
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self setupLayer];
[self setupContext];
[self setupRenderBuffer];
[self setupFrameBuffer];
[self compileShaders];
[self setupVBOs];
[self render];
}
return self;
}
- (void)setupVBOs {
float radius = 1;
float segments = 32;
float height = 10;
verticesCount = (int)segments*2*3;
// double Vertices[segments*2*3] = {};
cylinderVertices = malloc(sizeof(float) * verticesCount);
for (int i = 0; i < segments ; i++) {
float alpha = i / segments;
// x
cylinderVertices[3*i] = radius * cosf(alpha * 2.0 * M_PI);
// y
cylinderVertices[3*i+1] = radius * sinf(alpha * 2.0 * M_PI);
// z
cylinderVertices[3*i+2] = i % 2 ? height : - height;
}
GLuint vertexBuffer;
glGenBuffers(1, &vertexBuffer);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(cylinderVertices), cylinderVertices, GL_STATIC_DRAW);
// GLuint indexBuffer;
// glGenBuffers(1, &indexBuffer);
// glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
// glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices), Indices, GL_STATIC_DRAW);
}
@end
Raw
Vertex.glsl
attribute vec4 Position; // 1
attribute vec4 SourceColor; // 2
varying vec4 DestinationColor; // 3
uniform mat4 Projection;
void main(void) { // 4
DestinationColor = SourceColor; // 5
gl_Position = Position; // 6
}
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