X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fcode.git;a=blobdiff_plain;f=src%2Fshaderprogram.cpp;h=68a4767d648f26fc3c5514ac4c3cc8ab1f4dfde2;hp=7ccb9706f542e56da53629c5be4f19f56a3e34d1;hb=0ce8df17fae3ec986bd9570e5552aed92c080088;hpb=a851cf197844a2eb15fd5ee2c350ee296e415dca

diff --git a/src/shaderprogram.cpp b/src/shaderprogram.cpp
index 7ccb970..68a4767 100644
--- a/src/shaderprogram.cpp
+++ b/src/shaderprogram.cpp
@@ -1,55 +1,137 @@
 #include "shaderprogram.h"
+#include "log.h"
 
 using namespace IPDF;
 
+/**
+ * Initialise a shader program using GLSL source files
+ * @param geometry_file GLSL source for Geometry shader (optional)
+ * @param vertex_file GLSL source for vertex shader
+ * @param fragment_file GLSL source for fragment shader
+ * If a filename is the empty string it will be ignored
+ */
+bool ShaderProgram::InitialiseShaders(const char * vertex_file, const char * fragment_file, const char * geometry_file)
+{
+	if (m_valid)
+	{
+		Error("Shader already valid?");
+	}
+	m_program = glCreateProgram();
+	if (m_program == 0)
+	{
+		Error("glCreateProgram failed");
+		m_valid = false;
+		return m_valid;
+	}
+	m_valid = true;
+	if (geometry_file != NULL && geometry_file[0] != '\0')
+		m_valid &= AttachShader(geometry_file, GL_GEOMETRY_SHADER);
+	if (vertex_file != NULL && vertex_file[0] != '\0')
+		m_valid &= AttachShader(vertex_file, GL_VERTEX_SHADER);
+	if (fragment_file != NULL && fragment_file[0] != '\0')
+		m_valid &= AttachShader(fragment_file, GL_FRAGMENT_SHADER);
+
+	if (!m_valid)
+	{
+		Warn("One or more AttachShader calls failed but we will link the shader anyway");
+	}
+	glLinkProgram(m_program);
+	return m_valid;
+}
+
+
+
+/**
+ * Destroy a shader program
+ */
 ShaderProgram::~ShaderProgram()
 {
-	for(auto shader : m_shaders)
+	m_valid = false;
+	for(auto shader = m_shaders.begin(); shader != m_shaders.end(); ++shader)
 	{
-		glDetachShader(m_program, shader.obj);
-		glDeleteShader(shader.obj);
+		glDetachShader(m_program, shader->obj);
+		glDeleteShader(shader->obj);
 	}
 
 	if (m_program)
 		glDeleteProgram(m_program);
 }
 
-void ShaderProgram::LazyCreateProgram()
+/**
+ * Get GLSL shader source from a file as a string
+ * @param src_file filename to get the shader source from
+ * @returns a char* string allocated with new[] (remember to delete[] it)
+ */
+char * ShaderProgram::GetShaderSource(const char * src_file) const
 {
-	if (!m_program)
+	char * src = NULL;
+	FILE * file = fopen(src_file, "r");
+	if (file == NULL)
 	{
-		m_program = glCreateProgram();
+		Error("Could not open shader source file \"%s\": %s", src_file, strerror(errno));
+		return NULL;
 	}
+	long start = ftell(file);
+
+	if (fseek(file, 0, SEEK_END) != 0)
+	{
+		Error("Couldn't seek to end of file \"%s\": %s", src_file, strerror(errno));
+		return NULL;
+	}
+	long end = ftell(file);
+	if (start < 0 || end < 0 || end < start)
+	{
+		// I bet that now I've put this message here, it will occur at least once in the life of this code
+		Error("Insane results from ftell(3) on file \"%s\"", src_file);
+		return NULL;
+	}
+	size_t size = end - start;
+	src = new char[size+1]; // Warning! Allocation of memory occuring! We might all die!
+	rewind(file);
+	if (fread(src, 1,size, file) != size)
+	{
+		Error("Error in fread on \"%s\": %s", src_file, strerror(errno));
+		fclose(file);
+		delete [] src;
+		return NULL;
+	}
+	src[size] = '\0';
+	fclose(file);
+	return src;
+	
 }
 
-bool ShaderProgram::AttachShader(const char *src, GLenum type)
+bool ShaderProgram::AttachShader(const char * src_file, GLenum type)
 {
 	GLuint shader_obj = glCreateShader(type);
+	glObjectLabel(GL_SHADER, shader_obj, -1, src_file);
+	char * src = GetShaderSource(src_file);
+	if (src == NULL)
+	{
+		Error("Couldn't get shader source.");
+		return false;
+	}
+	
+
 	glShaderSource(shader_obj, 1, &src, 0);
 	glCompileShader(shader_obj);
+	int did_compile = 0;
+	glGetShaderiv(shader_obj, GL_COMPILE_STATUS, &did_compile);
+	delete [] src; // Oh my goodness memory management is hard guys
+	if (!did_compile)
+	{
+		char info_log[2048];
+
+		glGetShaderInfoLog(shader_obj, 2048, NULL, info_log);
+		Error("Shader compile error (file \"%s\"): %s (type %d)", src_file, info_log, type);
+		return false;
+	}
 
 	m_shaders.push_back(Shader{type, shader_obj});
-	LazyCreateProgram();
 	glAttachShader(m_program, shader_obj);
 	return true;
 }
 
-bool ShaderProgram::AttachVertexProgram(const char *src)
-{
-	return AttachShader(src, GL_VERTEX_SHADER);
-}
-
-bool ShaderProgram::AttachFragmentProgram(const char *src)
-{
-	return AttachShader(src, GL_FRAGMENT_SHADER);
-}
-
-bool ShaderProgram::Link()
-{
-	glLinkProgram(m_program);
-	return true;
-}
-
 const void ShaderProgram::Use() const
 {
 	glUseProgram(m_program);