Inner step of multiplication in x64 assembly

[ipdf/code.git] / src / shaderprogram.cpp

diff --git a/src/shaderprogram.cpp b/src/shaderprogram.cpp
index eb7a82d..0a5cb2e 100644 (file)
--- a/src/shaderprogram.cpp
+++ b/src/shaderprogram.cpp
@@ -3,8 +3,50 @@
 
 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()
 {
+       m_valid = false;
        for(auto shader : m_shaders)
        {
                glDetachShader(m_program, shader.obj);
@@ -15,57 +57,80 @@ ShaderProgram::~ShaderProgram()
                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)
+       {
+               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)
        {
-               m_program = glCreateProgram();
+               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);
+       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, nullptr, info_log);
-               Error("Shader compile error: %s\n", 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::AttachGeometryProgram(const char *src)
-{
-       return AttachShader(src, GL_GEOMETRY_SHADER);
-}
-
-bool ShaderProgram::Link()
-{
-       glLinkProgram(m_program);
-       return true;
-}
-
 const void ShaderProgram::Use() const
 {
        glUseProgram(m_program);