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Diffstat (limited to 'backends/graphics/opengl/shader.cpp')
| -rw-r--r-- | backends/graphics/opengl/shader.cpp | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/backends/graphics/opengl/shader.cpp b/backends/graphics/opengl/shader.cpp new file mode 100644 index 0000000000..6e36307860 --- /dev/null +++ b/backends/graphics/opengl/shader.cpp @@ -0,0 +1,176 @@ +/* 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_GL && !USE_FORCED_GLES + +#include "common/textconsole.h" + +namespace OpenGL { + +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 lowp vec2 texCoord;\n" + "varying lowp vec4 blendColor;\n" + "\n" + "uniform sampler2D texture;\n" + "\n" + "void main(void) {\n" + "\tgl_FragColor = blendColor * texture2D(texture, texCoord);\n" + "}\n"; + +Shader::Shader(const Common::String &vertex, const Common::String &fragment) + : _vertex(vertex), _fragment(fragment), _program(0), _projectionLocation(-1), _textureLocation(-1) { +} + +void Shader::destroy() { + GL_CALL(glDeleteProgram(_program)); + _program = 0; +} + +bool Shader::recreate() { + // Make sure any old programs are destroyed properly. + destroy(); + + GLuint vertexShader = compileShader(_vertex.c_str(), GL_VERTEX_SHADER); + if (!vertexShader) { + return false; + } + + GLuint 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(glBindAttribLocation(_program, kPositionAttribLocation, "position")); + GL_CALL(glBindAttribLocation(_program, kTexCoordAttribLocation, "texCoordIn")); + GL_CALL(glBindAttribLocation(_program, kColorAttribLocation, "blendColorIn")); + + 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; + } + + GL_ASSIGN(_projectionLocation, glGetUniformLocation(_program, "projection")); + if (_projectionLocation == -1) { + warning("Shader misses \"projection\" uniform."); + destroy(); + return false; + } + + GL_ASSIGN(_textureLocation, glGetUniformLocation(_program, "texture")); + if (_textureLocation == -1) { + warning("Shader misses \"texture\" uniform."); + destroy(); + return false; + } + + return true; +} + +void Shader::activate(const GLfloat *projectionMatrix) { + // Activate program. + GL_CALL(glUseProgram(_program)); + + // Set projection matrix. + GL_CALL(glUniformMatrix4fv(_projectionLocation, 1, GL_FALSE, projectionMatrix)); + + // We always use texture unit 0. + GL_CALL(glUniform1i(_textureLocation, 0)); +} + +GLuint Shader::compileShader(const char *source, GLenum shaderType) { + GLuint handle; + GL_ASSIGN(handle, glCreateShader(shaderType)); + if (!handle) { + return 0; + } + + GL_CALL(glShaderSource(handle, 1, &source, 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; +} + +} // End of namespace OpenGL + +#endif // !USE_FORCED_GL && !USE_FORCED_GLES |