scummvm/backends/graphics/opengl/pipelines/shader.cpp
Le Philousophe 70cf4e9e3e BACKENDS: OPENGL: Move framebuffer out of common activate code
This allows more control over activation process.
2022-11-06 20:02:59 +01:00

103 lines
3.6 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/pipelines/shader.h"
#include "backends/graphics/opengl/shader.h"
#include "backends/graphics/opengl/framebuffer.h"
#include "graphics/opengl/debug.h"
namespace OpenGL {
// A 4 elements with 2 components vector of floats
static const int kCoordinatesSize = 4 * 2 * sizeof(float);
#if !USE_FORCED_GLES
ShaderPipeline::ShaderPipeline(Shader *shader)
: _activeShader(shader), _colorAttributes() {
// Use the same VBO for vertices and texcoords as we modify them at the same time
_coordsVBO = OpenGL::Shader::createBuffer(GL_ARRAY_BUFFER, kCoordinatesSize, nullptr, GL_STATIC_DRAW);
_activeShader->enableVertexAttribute("position", _coordsVBO, 2, GL_FLOAT, GL_FALSE, 0, 0);
_texcoordsVBO = OpenGL::Shader::createBuffer(GL_ARRAY_BUFFER, kCoordinatesSize, nullptr, GL_STATIC_DRAW);
_activeShader->enableVertexAttribute("texCoordIn", _texcoordsVBO, 2, GL_FLOAT, GL_FALSE, 0, 0);
_colorVBO = OpenGL::Shader::createBuffer(GL_ARRAY_BUFFER, sizeof(_colorAttributes), nullptr, GL_DYNAMIC_DRAW);
_activeShader->enableVertexAttribute("blendColorIn", _colorVBO, 4, GL_FLOAT, GL_FALSE, 0, 0);
}
ShaderPipeline::~ShaderPipeline() {
delete _activeShader;
OpenGL::Shader::freeBuffer(_coordsVBO);
OpenGL::Shader::freeBuffer(_texcoordsVBO);
OpenGL::Shader::freeBuffer(_colorVBO);
}
void ShaderPipeline::activateInternal() {
Pipeline::activateInternal();
if (OpenGLContext.multitextureSupported) {
GL_CALL(glActiveTexture(GL_TEXTURE0));
}
_activeShader->use();
GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, _colorVBO));
GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(_colorAttributes), _colorAttributes));
GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, 0));
}
void ShaderPipeline::deactivateInternal() {
_activeShader->unbind();
Pipeline::deactivateInternal();
}
void ShaderPipeline::setColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a) {
GLfloat *dst = _colorAttributes;
for (uint i = 0; i < 4; ++i) {
*dst++ = r;
*dst++ = g;
*dst++ = b;
*dst++ = a;
}
}
void ShaderPipeline::drawTextureInternal(const GLTexture &texture, const GLfloat *coordinates, const GLfloat *texcoords) {
assert(isActive());
texture.bind();
GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, _coordsVBO));
GL_CALL(glBufferData(GL_ARRAY_BUFFER, kCoordinatesSize, coordinates, GL_STATIC_DRAW));
GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, _texcoordsVBO));
GL_CALL(glBufferData(GL_ARRAY_BUFFER, kCoordinatesSize, texcoords, GL_STATIC_DRAW));
GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, 0));
GL_CALL(glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
}
void ShaderPipeline::setProjectionMatrix(const Math::Matrix4 &projectionMatrix) {
assert(isActive());
_activeShader->setUniform("projection", projectionMatrix);
}
#endif // !USE_FORCED_GLES
} // End of namespace OpenGL