OPENGL: Support GLES2 contexts.

backends/graphics/opengl/shader.h

@@ -0,0 +1,110 @@
+/* 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_GL && !USE_FORCED_GLES
+
+#include "common/str.h"
+
+namespace OpenGL {
+
+enum {
+	kPositionAttribLocation = 0,
+	kTexCoordAttribLocation = 1,
+	kColorAttribLocation    = 2
+};
+
+extern const char *const g_defaultVertexShader;
+extern const char *const g_defaultFragmentShader;
+
+class Shader {
+public:
+	Shader(const Common::String &vertex, const Common::String &fragment);
+	~Shader() { destroy(); }
+
+	/**
+	 * Destroy the shader program.
+	 *
+	 * This keeps the vertex and fragment shader sources around and thus
+	 * allows for recreating the shader on context recreation.
+	 */
+	void destroy();
+
+	/**
+	 * Recreate shader program.
+	 *
+	 * @return true on success, false on failure.
+	 */
+	bool recreate();
+
+	/**
+	 * Make shader active.
+	 *
+	 * @param projectionMatrix Projection matrix to use.
+	 */
+	void activate(const GLfloat *projectionMatrix);
+private:
+	/**
+	 * Vertex shader sources.
+	 */
+	const Common::String _vertex;
+
+	/**
+	 * Fragment shader sources.
+	 */
+	const Common::String _fragment;
+
+	/**
+	 * Shader program handle.
+	 */
+	GLuint _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 or
+	 *                   GL_VERTEX_SHADER)
+	 * @return The shader object or 0 on failure.
+	 */
+	static GLuint compileShader(const char *source, GLenum shaderType);
+};
+
+} // End of namespace OpenGL
+
+#endif // !USE_FORCED_GL && !USE_FORCED_GLES
+
+#endif