// Creates program object, attaches shaders, and links into pipeline
protected int createProgram(String vertexSource, String fragmentSource) {
// Load the vertex and fragment shaders
int vertexShader = loadShader(GL_VERTEX_SHADER, vertexSource);
int fragmentShader = loadShader(GL_FRAGMENT_SHADER, fragmentSource);
// Create the program object
int program = glCreateProgram();
if (vertexShader == 0 || fragmentShader == 0 || program == 0) return 0;
if (program != 0) {
glAttachShader(program, vertexShader);
ctx.checkGLError("createProgram Attaching vertex shader");
glAttachShader(program, fragmentShader);
ctx.checkGLError("createProgram Attaching fragment shader");
glLinkProgram(program);
int linkStatus = glGetProgram(program, GL_LINK_STATUS);
if (linkStatus != GL_TRUE) {
log().error("Could not link program: ");
log().error(glGetProgramInfoLog(program, SHADER_INFO_LOG_LEN));
glDeleteProgram(program);
program = 0;
}
}
return program;
}
protected boolean prepare(int fbufWidth, int fbufHeight) {
if (ctx.useShader(this) && glIsProgram(program)) {
glUseProgram(program);
ctx.checkGLError("Shader.prepare useProgram");
glUniform2f(uScreenSizeLoc, fbufWidth, fbufHeight);
// ctx.checkGLError("Shader.prepare uScreenSizeLoc set to " + fbufWidth + " " + fbufHeight);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementBuffer);
ctx.checkGLError("Shader.prepare BindBuffer");
glEnableVertexAttribArray(aMatrix);
glEnableVertexAttribArray(aTranslation);
glEnableVertexAttribArray(aPosition);
if (aTexture != -1) glEnableVertexAttribArray(aTexture);
ctx.checkGLError("Shader.prepare AttribArrays enabled");
glVertexAttribPointer(aMatrix, 4, GL_FLOAT, false, VERTEX_STRIDE, 0);
glVertexAttribPointer(aTranslation, 2, GL_FLOAT, false, VERTEX_STRIDE, 16);
glVertexAttribPointer(aPosition, 2, GL_FLOAT, false, VERTEX_STRIDE, 24);
if (aTexture != -1) glVertexAttribPointer(aTexture, 2, GL_FLOAT, false, VERTEX_STRIDE, 32);
ctx.checkGLError("Shader.prepare AttribPointer");
return true;
}
return false;
}
@Override
public void flush() {
if (vertexOffset == 0) {
return;
}
ctx.checkGLError("Shader.flush");
vertexData.position(0);
glBufferData(GL_ARRAY_BUFFER, vertexData, GL_STREAM_DRAW);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, elementData, GL_STREAM_DRAW);
ctx.checkGLError("Shader.flush BufferData");
glDrawElements(GL_TRIANGLES, elementOffset, GL_UNSIGNED_SHORT, 0);
vertexOffset = elementOffset = 0;
ctx.checkGLError("Shader.flush DrawElements");
}