scummvm/backends/graphics/opengl/shader.cpp

127 lines
3.4 KiB
C++

/* 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 adjustFactor = 255.0 / 256.0 + 1.0 / (2.0 * 256.0);"
"\n"
"void main(void) {\n"
"\tvec4 index = texture2D(shaderTexture, texCoord);\n"
"\tgl_FragColor = blendColor * texture2D(palette, vec2(index.a * adjustFactor, 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