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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 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.
+ *
+ */
+
+#include "backends/graphics/opengl/shader.h"
+
+#if !USE_FORCED_GLES
+
+#include "common/textconsole.h"
+#include "common/util.h"
+
+namespace Common {
+DECLARE_SINGLETON(OpenGL::ShaderManager);
+}
+
+namespace OpenGL {
+
+namespace {
+
+#pragma mark - Builtin Shader Sources -
+
+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 texture;\n"
+ "\n"
+ "void main(void) {\n"
+ "\tgl_FragColor = blendColor * texture2D(texture, texCoord);\n"
+ "}\n";
+
+const char *const g_lookUpFragmentShader =
+ "varying vec2 texCoord;\n"
+ "varying vec4 blendColor;\n"
+ "\n"
+ "uniform sampler2D texture;\n"
+ "uniform sampler2D palette;\n"
+ "\n"
+ "const float adjustFactor = 255.0 / 256.0 + 1.0 / (2.0 * 256.0);"
+ "\n"
+ "void main(void) {\n"
+ "\tvec4 index = texture2D(texture, texCoord);\n"
+ "\tgl_FragColor = blendColor * texture2D(palette, vec2(index.a * adjustFactor, 0.0));\n"
+ "}\n";
+
+
+// Taken from: https://en.wikibooks.org/wiki/OpenGL_Programming/Modern_OpenGL_Tutorial_03#OpenGL_ES_2_portability
+const char *const g_precisionDefines =
+ "#ifdef GL_ES\n"
+ "\t#if defined(GL_FRAGMENT_PRECISION_HIGH) && GL_FRAGMENT_PRECISION_HIGH == 1\n"
+ "\t\tprecision highp float;\n"
+ "\t#else\n"
+ "\t\tprecision mediump float;\n"
+ "\t#endif\n"
+ "#else\n"
+ "\t#define highp\n"
+ "\t#define mediump\n"
+ "\t#define lowp\n"
+ "#endif\n";
+
+} // End of anonymous namespace
+
+#pragma mark - Uniform Values -
+
+void ShaderUniformInteger::set(GLint location) const {
+ GL_CALL(glUniform1i(location, _value));
+}
+
+void ShaderUniformFloat::set(GLint location) const {
+ GL_CALL(glUniform1f(location, _value));
+}
+
+void ShaderUniformMatrix44::set(GLint location) const {
+ GL_CALL(glUniformMatrix4fv(location, 1, GL_FALSE, _matrix));
+}
+
+#pragma mark - Shader Implementation -
+
+Shader::Shader(const Common::String &vertex, const Common::String &fragment)
+ : _vertex(vertex), _fragment(fragment), _isActive(false), _program(0), _uniforms() {
+ recreate();
+}
+
+Shader::~Shader() {
+ // According to extension specification glDeleteObjectARB silently ignores
+ // 0. However, with nVidia drivers this can cause GL_INVALID_VALUE, thus
+ // we do not call it with 0 as parameter to avoid warnings.
+ if (_program) {
+ GL_CALL_SAFE(glDeleteProgram, (_program));
+ }
+}
+
+void Shader::destroy() {
+ // According to extension specification glDeleteObjectARB silently ignores
+ // 0. However, with nVidia drivers this can cause GL_INVALID_VALUE, thus
+ // we do not call it with 0 as parameter to avoid warnings.
+ if (_program) {
+ GL_CALL(glDeleteProgram(_program));
+ _program = 0;
+ }
+}
+
+bool Shader::recreate() {
+ // Make sure any old programs are destroyed properly.
+ destroy();
+
+ GLshader vertexShader = compileShader(_vertex.c_str(), GL_VERTEX_SHADER);
+ if (!vertexShader) {
+ return false;
+ }
+
+ GLshader fragmentShader = compileShader(_fragment.c_str(), GL_FRAGMENT_SHADER);
+ if (!fragmentShader) {
+ GL_CALL(glDeleteShader(vertexShader));
+ return false;
+ }
+
+ GL_ASSIGN(_program, glCreateProgram());
+ if (!_program) {
+ GL_CALL(glDeleteShader(vertexShader));
+ GL_CALL(glDeleteShader(fragmentShader));
+ return false;
+ }
+
+ GL_CALL(glAttachShader(_program, vertexShader));
+ GL_CALL(glAttachShader(_program, fragmentShader));
+
+ GL_CALL(glLinkProgram(_program));
+
+ GL_CALL(glDetachShader(_program, fragmentShader));
+ GL_CALL(glDeleteShader(fragmentShader));
+
+ GL_CALL(glDetachShader(_program, vertexShader));
+ GL_CALL(glDeleteShader(vertexShader));
+
+ GLint result;
+ GL_CALL(glGetProgramiv(_program, GL_LINK_STATUS, &result));
+ if (result == GL_FALSE) {
+ GLint logSize;
+ GL_CALL(glGetProgramiv(_program, GL_INFO_LOG_LENGTH, &logSize));
+
+ GLchar *log = new GLchar[logSize];
+ GL_CALL(glGetProgramInfoLog(_program, logSize, nullptr, log));
+ warning("Could not link shader: \"%s\"", log);
+ delete[] log;
+
+ destroy();
+ return false;
+ }
+
+ // Set program object in case shader is active during recreation.
+ if (_isActive) {
+ GL_CALL(glUseProgram(_program));
+ }
+
+ for (UniformMap::iterator i = _uniforms.begin(), end = _uniforms.end(); i != end; ++i) {
+ i->_value.location = getUniformLocation(i->_key.c_str());
+ i->_value.altered = true;
+ if (_isActive) {
+ i->_value.set();
+ }
+ }
+
+ return true;
+}
+
+void Shader::activate() {
+ // Activate program.
+ GL_CALL(glUseProgram(_program));
+
+ // Reset changed uniform values.
+ for (UniformMap::iterator i = _uniforms.begin(), end = _uniforms.end(); i != end; ++i) {
+ i->_value.set();
+ }
+
+ _isActive = true;
+}
+
+void Shader::deactivate() {
+ _isActive = false;
+}
+
+GLint Shader::getAttributeLocation(const char *name) const {
+ GLint result = -1;
+ GL_ASSIGN(result, glGetAttribLocation(_program, name));
+ return result;
+}
+
+GLint Shader::getUniformLocation(const char *name) const {
+ GLint result = -1;
+ GL_ASSIGN(result, glGetUniformLocation(_program, name));
+ return result;
+}
+
+bool Shader::setUniform(const Common::String &name, ShaderUniformValue *value) {
+ UniformMap::iterator uniformIter = _uniforms.find(name);
+ Uniform *uniform;
+
+ if (uniformIter == _uniforms.end()) {
+ const GLint location = getUniformLocation(name.c_str());
+ if (location == -1) {
+ delete value;
+ return false;
+ }
+
+ uniform = &_uniforms[name];
+ uniform->location = location;
+ } else {
+ uniform = &uniformIter->_value;
+ }
+
+ uniform->value = Common::SharedPtr<ShaderUniformValue>(value);
+ uniform->altered = true;
+ if (_isActive) {
+ uniform->set();
+ }
+
+ return true;
+}
+
+GLshader Shader::compileShader(const char *source, GLenum shaderType) {
+ GLshader handle;
+ GL_ASSIGN(handle, glCreateShader(shaderType));
+ if (!handle) {
+ return 0;
+ }
+
+ const char *const sources[2] = {
+ g_precisionDefines,
+ source
+ };
+
+ GL_CALL(glShaderSource(handle, ARRAYSIZE(sources), sources, nullptr));
+ GL_CALL(glCompileShader(handle));
+
+ GLint result;
+ GL_CALL(glGetShaderiv(handle, GL_COMPILE_STATUS, &result));
+ if (result == GL_FALSE) {
+ GLint logSize;
+ GL_CALL(glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &logSize));
+
+ GLchar *log = new GLchar[logSize];
+ GL_CALL(glGetShaderInfoLog(handle, logSize, nullptr, log));
+ warning("Could not compile shader \"%s\": \"%s\"", source, log);
+ delete[] log;
+
+ GL_CALL(glDeleteShader(handle));
+ return 0;
+ }
+
+ return handle;
+}
+
+ShaderManager::ShaderManager() : _initializeShaders(true) {
+}
+
+ShaderManager::~ShaderManager() {
+ for (int i = 0; i < ARRAYSIZE(_builtIn); ++i) {
+ delete _builtIn[i];
+ }
+}
+
+void ShaderManager::notifyDestroy() {
+ for (int i = 0; i < ARRAYSIZE(_builtIn); ++i) {
+ _builtIn[i]->destroy();
+ }
+}
+
+void ShaderManager::notifyCreate() {
+ if (_initializeShaders) {
+ _initializeShaders = false;
+
+ _builtIn[kDefault] = new Shader(g_defaultVertexShader, g_defaultFragmentShader);
+ _builtIn[kCLUT8LookUp] = new Shader(g_defaultVertexShader, g_lookUpFragmentShader);
+ _builtIn[kCLUT8LookUp]->setUniform1I("palette", 1);
+
+ for (uint i = 0; i < kMaxUsages; ++i) {
+ _builtIn[i]->setUniform1I("texture", 0);
+ }
+ } else {
+ for (int i = 0; i < ARRAYSIZE(_builtIn); ++i) {
+ _builtIn[i]->recreate();
+ }
+ }
+}
+
+Shader *ShaderManager::query(ShaderUsage shader) const {
+ if (shader == kMaxUsages) {
+ warning("OpenGL: ShaderManager::query used with kMaxUsages");
+ return nullptr;
+ }
+
+ return _builtIn[shader];
+}
+
+} // End of namespace OpenGL
+
+#endif // !USE_FORCED_GLES