Initial commit

backends/graphics/opengl/shader.cpp

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+/* 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "backends/graphics/opengl/shader.h"
+#include "graphics/opengl/debug.h"
+
+#if !USE_FORCED_GLES
+
+namespace Common {
+DECLARE_SINGLETON(OpenGL::ShaderManager);
+}
+
+namespace OpenGL {
+
+namespace {
+
+#pragma mark - Builtin Shader Sources -
+
+const char *const g_defaultShaderAttributes[] = {
+	"position", "texCoordIn", "blendColorIn", nullptr
+};
+
+const char *const g_defaultVertexShader =
+	"attribute vec4 position;\n"
+	"attribute vec2 texCoordIn;\n"
+	"attribute vec4 blendColorIn;\n"
+	"\n"
+	"uniform mat4 projection;\n"
+	"\n"
+	"varying vec2 texCoord;\n"
+	"varying vec4 blendColor;\n"
+	"\n"
+	"void main(void) {\n"
+	"\ttexCoord    = texCoordIn;\n"
+	"\tblendColor  = blendColorIn;\n"
+	"\tgl_Position = projection * position;\n"
+	"}\n";
+
+const char *const g_defaultFragmentShader =
+	"varying vec2 texCoord;\n"
+	"varying vec4 blendColor;\n"
+	"\n"
+	"uniform sampler2D shaderTexture;\n"
+	"\n"
+	"void main(void) {\n"
+	"\tgl_FragColor = blendColor * texture2D(shaderTexture, texCoord);\n"
+	"}\n";
+
+const char *const g_lookUpFragmentShader =
+	"varying vec2 texCoord;\n"
+	"varying vec4 blendColor;\n"
+	"\n"
+	"uniform sampler2D shaderTexture;\n"
+	"uniform sampler2D palette;\n"
+	"\n"
+	"const float scaleFactor = 255.0 / 256.0;\n"
+	"const float offsetFactor = 1.0 / (2.0 * 256.0);\n"
+	"\n"
+	"void main(void) {\n"
+	"\tvec4 index = texture2D(shaderTexture, texCoord);\n"
+	"\tgl_FragColor = blendColor * texture2D(palette, vec2(index.a * scaleFactor + offsetFactor, 0.0));\n"
+	"}\n";
+
+} // End of anonymous namespace
+
+ShaderManager::ShaderManager() {
+	for (int i = 0; i < ARRAYSIZE(_builtIn); ++i) {
+		_builtIn[i] = nullptr;
+	}
+}
+
+ShaderManager::~ShaderManager() {
+	for (int i = 0; i < ARRAYSIZE(_builtIn); ++i) {
+		delete _builtIn[i];
+	}
+}
+
+void ShaderManager::notifyDestroy() {
+	for (int i = 0; i < ARRAYSIZE(_builtIn); ++i) {
+		delete _builtIn[i];
+		_builtIn[i] = nullptr;
+	}
+}
+
+void ShaderManager::notifyCreate() {
+	// Ensure everything is destroyed
+	notifyDestroy();
+
+	_builtIn[kDefault] = Shader::fromStrings("default", g_defaultVertexShader, g_defaultFragmentShader, g_defaultShaderAttributes, 110);
+	_builtIn[kCLUT8LookUp] = Shader::fromStrings("clut8lookup", g_defaultVertexShader, g_lookUpFragmentShader, g_defaultShaderAttributes, 110);
+	_builtIn[kCLUT8LookUp]->setUniform("palette", 1);
+
+	for (uint i = 0; i < kMaxUsages; ++i) {
+		_builtIn[i]->setUniform("shaderTexture", 0);
+	}
+}
+
+Shader *ShaderManager::query(ShaderUsage shader) const {
+	if (shader == kMaxUsages) {
+		warning("OpenGL: ShaderManager::query used with kMaxUsages");
+		return nullptr;
+	}
+
+	assert(_builtIn[shader]);
+	return _builtIn[shader]->clone();
+}
+
+} // End of namespace OpenGL
+
+#endif // !USE_FORCED_GLES