OPENGL: Add support for shaders with GL contexts.

1 files changed, 68 insertions, 9 deletions

diff --git a/backends/graphics/opengl/shader.h b/backends/graphics/opengl/shader.h
index e8535e0225..8c457f8f91 100644
--- a/backends/graphics/opengl/shader.h
+++ b/backends/graphics/opengl/shader.h
@@ -25,7 +25,7 @@
 
 #include "backends/graphics/opengl/opengl-sys.h"
 
-#if !USE_FORCED_GL && !USE_FORCED_GLES
+#if !USE_FORCED_GLES
 
 #include "common/str.h"
 
@@ -38,12 +38,18 @@ enum {
 };
 
 extern const char *const g_defaultVertexShader;
-extern const char *const g_defaultFragmentShader;
+#if !USE_FORCED_GLES2
+extern const char *const g_defaultFragmentShaderGL;
+#endif
+#if !USE_FORCED_GL
+extern const char *const g_defaultFragmentShaderGLES2;
+#endif
 
 class Shader {
 public:
-	Shader(const Common::String &vertex, const Common::String &fragment);
-	~Shader() { destroy(); }
+	Shader(const Common::String &vertex, const Common::String &fragment)
+	    : _vertex(vertex), _fragment(fragment) {}
+	virtual ~Shader() {}
 
 	/**
 	 * Destroy the shader program.
@@ -51,22 +57,22 @@ public:
 	 * This keeps the vertex and fragment shader sources around and thus
 	 * allows for recreating the shader on context recreation.
 	 */
-	void destroy();
+	virtual void destroy() = 0;
 
 	/**
 	 * Recreate shader program.
 	 *
 	 * @return true on success, false on failure.
 	 */
-	bool recreate();
+	virtual bool recreate() = 0;
 
 	/**
 	 * Make shader active.
 	 *
 	 * @param projectionMatrix Projection matrix to use.
 	 */
-	void activate(const GLfloat *projectionMatrix);
-private:
+	virtual void activate(const GLfloat *projectionMatrix) = 0;
+protected:
 	/**
 	 * Vertex shader sources.
 	 */
@@ -76,7 +82,59 @@ private:
 	 * Fragment shader sources.
 	 */
 	const Common::String _fragment;
+};
+
+#if !USE_FORCED_GLES2
+class ShaderARB : public Shader {
+public:
+	ShaderARB(const Common::String &vertex, const Common::String &fragment);
+	virtual ~ShaderARB() { destroy(); }
+
+	virtual void destroy();
+
+	virtual bool recreate();
 
+	virtual void activate(const GLfloat *projectionMatrix);
+private:
+	/**
+	 * Shader program handle.
+	 */
+	GLhandleARB _program;
+
+	/**
+	 * Location of the matrix uniform in the shader program.
+	 */
+	GLint _projectionLocation;
+
+	/**
+	 * Location of the texture sampler location in the shader program.
+	 */
+	GLint _textureLocation;
+
+	/**
+	 * Compile a vertex or fragment shader.
+	 *
+	 * @param source     Sources to the shader.
+	 * @param shaderType Type of shader to compile (GL_FRAGMENT_SHADER_ARB or
+	 *                   GL_VERTEX_SHADER_ARB)
+	 * @return The shader object or 0 on failure.
+	 */
+	static GLhandleARB compileShader(const char *source, GLenum shaderType);
+};
+#endif // !USE_FORCED_GLES2
+
+#if !USE_FORCED_GL
+class ShaderGLES2 : public Shader {
+public:
+	ShaderGLES2(const Common::String &vertex, const Common::String &fragment);
+	virtual ~ShaderGLES2() { destroy(); }
+
+	virtual void destroy();
+
+	virtual bool recreate();
+
+	virtual void activate(const GLfloat *projectionMatrix);
+private:
 	/**
 	 * Shader program handle.
 	 */
@@ -102,9 +160,10 @@ private:
 	 */
 	static GLuint compileShader(const char *source, GLenum shaderType);
 };
+#endif
 
 } // End of namespace OpenGL
 
-#endif // !USE_FORCED_GL && !USE_FORCED_GLES
+#endif // !USE_FORCED_GLES
 
 #endif