1 files changed, 288 insertions, 0 deletions
diff --git a/backends/graphics/opengl/shader.h b/backends/graphics/opengl/shader.h
new file mode 100644
index 0000000000..ec1e516d14
--- /dev/null
+++ b/backends/graphics/opengl/shader.h
@@ -0,0 +1,288 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef BACKENDS_GRAPHICS_OPENGL_SHADER_H
+#define BACKENDS_GRAPHICS_OPENGL_SHADER_H
+
+#include "backends/graphics/opengl/opengl-sys.h"
+
+#if !USE_FORCED_GLES
+
+#include "common/singleton.h"
+#include "common/hash-str.h"
+#include "common/ptr.h"
+
+namespace OpenGL {
+
+/**
+ * A generic uniform value interface for a shader program.
+ */
+class ShaderUniformValue {
+public:
+	virtual ~ShaderUniformValue() {}
+
+	/**
+	 * Setup the the value to the given location.
+	 *
+	 * @param location Location of the uniform.
+	 */
+	virtual void set(GLint location) const = 0;
+};
+
+/**
+ * Integer value for a shader uniform.
+ */
+class ShaderUniformInteger : public ShaderUniformValue {
+public:
+	ShaderUniformInteger(GLint value) : _value(value) {}
+
+	virtual void set(GLint location) const override;
+
+private:
+	const GLint _value;
+};
+
+/**
+ * Float value for a shader uniform.
+ */
+class ShaderUniformFloat : public ShaderUniformValue {
+public:
+	ShaderUniformFloat(GLfloat value) : _value(value) {}
+
+	virtual void set(GLint location) const override;
+
+private:
+	const GLfloat _value;
+};
+
+/**
+ * 4x4 Matrix value for a shader uniform.
+ */
+class ShaderUniformMatrix44 : public ShaderUniformValue {
+public:
+	ShaderUniformMatrix44(const GLfloat *mat44) {
+		memcpy(_matrix, mat44, sizeof(_matrix));
+	}
+
+	virtual void set(GLint location) const override;
+
+private:
+	GLfloat _matrix[4*4];
+};
+
+class Shader {
+public:
+	Shader(const Common::String &vertex, const Common::String &fragment);
+	~Shader();
+
+	/**
+	 * Destroy the shader program.
+	 *
+	 * This keeps the vertex and fragment shader sources around and thus
+	 * allows for recreating the shader on context recreation. It also keeps
+	 * the uniform state around.
+	 */
+	void destroy();
+
+	/**
+	 * Recreate shader program.
+	 *
+	 * @return true on success, false on failure.
+	 */
+	bool recreate();
+
+	/**
+	 * Make shader active.
+	 */
+	void activate();
+
+	/**
+	 * Make shader inactive.
+	 */
+	void deactivate();
+
+	/**
+	 * Return location for attribute with given name.
+	 *
+	 * @param name Name of the attribute to look up in the shader.
+	 * @return The loctaion of -1 if attribute was not found.
+	 */
+	GLint getAttributeLocation(const char *name) const;
+	GLint getAttributeLocation(const Common::String &name) const {
+		return getAttributeLocation(name.c_str());
+	}
+
+	/**
+	 * Return location for uniform with given name.
+	 *
+	 * @param name Name of the uniform to look up in the shader.
+	 * @return The location or -1 if uniform was not found.
+	 */
+	GLint getUniformLocation(const char *name) const;
+	GLint getUniformLocation(const Common::String &name) const {
+		return getUniformLocation(name.c_str());
+	}
+
+	/**
+	 * Bind value to uniform.
+	 *
+	 * @param name  The name of the uniform to be set.
+	 * @param value The value to be set.
+	 * @return 'false' on error (i.e. uniform unknown or otherwise),
+	 *         'true' otherwise.
+	 */
+	bool setUniform(const Common::String &name, ShaderUniformValue *value);
+
+	/**
+	 * Bind integer value to uniform.
+	 *
+	 * @param name  The name of the uniform to be set.
+	 * @param value The value to be set.
+	 * @return 'false' on error (i.e. uniform unknown or otherwise),
+	 *         'true' otherwise.
+	 */
+	bool setUniform1I(const Common::String &name, GLint value) {
+		return setUniform(name, new ShaderUniformInteger(value));
+	}
+protected:
+	/**
+	 * Vertex shader sources.
+	 */
+	const Common::String _vertex;
+
+	/**
+	 * Fragment shader sources.
+	 */
+	const Common::String _fragment;
+
+	/**
+	 * Whether the shader is active or not.
+	 */
+	bool _isActive;
+
+	/**
+	 * Shader program handle.
+	 */
+	GLprogram _program;
+
+	/**
+	 * A uniform descriptor.
+	 *
+	 * This stores the state of a shader uniform. The state is made up of the
+	 * uniform location, whether the state was altered since last set, and the
+	 * value of the uniform.
+	 */
+	struct Uniform {
+		Uniform() : location(-1), altered(false), value() {}
+		Uniform(GLint loc, ShaderUniformValue *val)
+		    : location(loc), altered(true), value(val) {}
+
+		/**
+		 * Write uniform value into currently active shader.
+		 */
+		void set() {
+			if (altered && value) {
+				value->set(location);
+				altered = false;
+			}
+		}
+
+		/**
+		 * The location of the uniform or -1 in case it does not exist.
+		 */
+		GLint location;
+
+		/**
+		 * Whether the uniform state was aletered since last 'set'.
+		 */
+		bool altered;
+
+		/**
+		 * The value of the uniform.
+		 */
+		Common::SharedPtr<ShaderUniformValue> value;
+	};
+
+	typedef Common::HashMap<Common::String, Uniform> UniformMap;
+
+	/**
+	 * Map from uniform name to associated uniform description.
+	 */
+	UniformMap _uniforms;
+
+	/**
+	 * 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 GLshader compileShader(const char *source, GLenum shaderType);
+};
+
+class ShaderManager : public Common::Singleton<ShaderManager> {
+public:
+	enum ShaderUsage {
+		/** Default shader implementing the GL fixed-function pipeline. */
+		kDefault = 0,
+
+		/** CLUT8 look up shader. */
+		kCLUT8LookUp,
+
+		/** Number of built-in shaders. Should not be used for query. */
+		kMaxUsages
+	};
+
+	/**
+	 * Notify shader manager about context destruction.
+	 */
+	void notifyDestroy();
+
+	/**
+	 * Notify shader manager about context creation.
+	 */
+	void notifyCreate();
+
+	/**
+	 * Query a built-in shader.
+	 */
+	Shader *query(ShaderUsage shader) const;
+
+private:
+	friend class Common::Singleton<SingletonBaseType>;
+	ShaderManager();
+	~ShaderManager();
+
+	bool _initializeShaders;
+
+	Shader *_builtIn[kMaxUsages];
+};
+
+} // End of namespace OpenGL
+
+/** Shortcut for accessing the font manager. */
+#define ShaderMan (OpenGL::ShaderManager::instance())
+
+#endif // !USE_FORCED_GLES
+
+#endif