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diff --git a/subprojects/d2tk/nanovg/src/nanovg_gl_utils.h b/subprojects/d2tk/nanovg/src/nanovg_gl_utils.h
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+//
+// 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);
+
+#if defined NANOVG_GL2
+ fb->texture = nvglImageHandleGL2(ctx, fb->image);
+#elif defined NANOVG_GL3
+ fb->texture = nvglImageHandleGL3(ctx, fb->image);
+#elif defined NANOVG_GLES2
+ fb->texture = nvglImageHandleGLES2(ctx, fb->image);
+#elif defined NANOVG_GLES3
+ fb->texture = nvglImageHandleGLES3(ctx, fb->image);
+#endif
+
+ 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) {
+#ifdef GL_DEPTH24_STENCIL8
+ // If GL_STENCIL_INDEX8 is not supported, try GL_DEPTH24_STENCIL8 as a fallback.
+ // Some graphics cards require a depth buffer along with a stencil.
+ glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, w, h);
+ 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)
+#endif // GL_DEPTH24_STENCIL8
+ 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