reactphysics3d/testbed/nanogui/ext/nanovg/src/nanovg_gl_utils.h

134 lines
3.9 KiB
C

//
// Copyright (c) 2009-2013 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//
#ifndef NANOVG_GL_UTILS_H
#define NANOVG_GL_UTILS_H
struct NVGLUframebuffer {
NVGcontext* ctx;
GLuint fbo;
GLuint rbo;
GLuint texture;
int image;
};
typedef struct NVGLUframebuffer NVGLUframebuffer;
// Helper function to create GL frame buffer to render to.
void nvgluBindFramebuffer(NVGLUframebuffer* fb);
NVGLUframebuffer* nvgluCreateFramebuffer(NVGcontext* ctx, int w, int h, int imageFlags);
void nvgluDeleteFramebuffer(NVGLUframebuffer* fb);
#endif // NANOVG_GL_UTILS_H
#ifdef NANOVG_GL_IMPLEMENTATION
#if defined(NANOVG_GL3) || defined(NANOVG_GLES2) || defined(NANOVG_GLES3)
// FBO is core in OpenGL 3>.
# define NANOVG_FBO_VALID 1
#elif defined(NANOVG_GL2)
// On OS X including glext defines FBO on GL2 too.
# ifdef __APPLE__
# include <OpenGL/glext.h>
# define NANOVG_FBO_VALID 1
# endif
#endif
static GLint defaultFBO = -1;
NVGLUframebuffer* nvgluCreateFramebuffer(NVGcontext* ctx, int w, int h, int imageFlags)
{
#ifdef NANOVG_FBO_VALID
GLint defaultFBO;
GLint defaultRBO;
NVGLUframebuffer* fb = NULL;
glGetIntegerv(GL_FRAMEBUFFER_BINDING, &defaultFBO);
glGetIntegerv(GL_RENDERBUFFER_BINDING, &defaultRBO);
fb = (NVGLUframebuffer*)malloc(sizeof(NVGLUframebuffer));
if (fb == NULL) goto error;
memset(fb, 0, sizeof(NVGLUframebuffer));
fb->image = nvgCreateImageRGBA(ctx, w, h, imageFlags | NVG_IMAGE_FLIPY | NVG_IMAGE_PREMULTIPLIED, NULL);
fb->texture = nvglImageHandle(ctx, fb->image);
fb->ctx = ctx;
// frame buffer object
glGenFramebuffers(1, &fb->fbo);
glBindFramebuffer(GL_FRAMEBUFFER, fb->fbo);
// render buffer object
glGenRenderbuffers(1, &fb->rbo);
glBindRenderbuffer(GL_RENDERBUFFER, fb->rbo);
glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX8, w, h);
// combine all
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, fb->texture, 0);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, fb->rbo);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) goto error;
glBindFramebuffer(GL_FRAMEBUFFER, defaultFBO);
glBindRenderbuffer(GL_RENDERBUFFER, defaultRBO);
return fb;
error:
glBindFramebuffer(GL_FRAMEBUFFER, defaultFBO);
glBindRenderbuffer(GL_RENDERBUFFER, defaultRBO);
nvgluDeleteFramebuffer(fb);
return NULL;
#else
NVG_NOTUSED(ctx);
NVG_NOTUSED(w);
NVG_NOTUSED(h);
NVG_NOTUSED(imageFlags);
return NULL;
#endif
}
void nvgluBindFramebuffer(NVGLUframebuffer* fb)
{
#ifdef NANOVG_FBO_VALID
if (defaultFBO == -1) glGetIntegerv(GL_FRAMEBUFFER_BINDING, &defaultFBO);
glBindFramebuffer(GL_FRAMEBUFFER, fb != NULL ? fb->fbo : defaultFBO);
#else
NVG_NOTUSED(fb);
#endif
}
void nvgluDeleteFramebuffer(NVGLUframebuffer* fb)
{
#ifdef NANOVG_FBO_VALID
if (fb == NULL) return;
if (fb->fbo != 0)
glDeleteFramebuffers(1, &fb->fbo);
if (fb->rbo != 0)
glDeleteRenderbuffers(1, &fb->rbo);
if (fb->image >= 0)
nvgDeleteImage(fb->ctx, fb->image);
fb->ctx = NULL;
fb->fbo = 0;
fb->rbo = 0;
fb->texture = 0;
fb->image = -1;
free(fb);
#else
NVG_NOTUSED(fb);
#endif
}
#endif // NANOVG_GL_IMPLEMENTATION