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authorTavian Barnes <tavianator@gmail.com>2009-07-02 04:53:40 +0000
committerTavian Barnes <tavianator@gmail.com>2009-07-02 04:53:40 +0000
commita7b2355c6424fff9093d238c973fb09d801da934 (patch)
tree8c0ab0153e063b86be36e9c8c055bb632c069e9a /libdimension/gl.c
parent4d9f72b850c7a86af3a8fb36ff8d48220a6a0914 (diff)
downloaddimension-a7b2355c6424fff9093d238c973fb09d801da934.tar.xz
Provide interface to export canvas to openGL.
Diffstat (limited to 'libdimension/gl.c')
-rw-r--r--libdimension/gl.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/libdimension/gl.c b/libdimension/gl.c
new file mode 100644
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+++ b/libdimension/gl.c
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+/*************************************************************************
+ * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com> *
+ * *
+ * This file is part of The Dimension Library. *
+ * *
+ * The Dimension Library is free software; you can redistribute it and/ *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version. *
+ * *
+ * The Dimension Library 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 *
+ * Lesser General Public License for more details. *
+ * *
+ * You should have received a copy of the GNU Lesser General Public *
+ * License along with this program. If not, see *
+ * <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+#include "dimension.h"
+#include <GL/gl.h>
+
+/* Write canvas to GL framebuffer. Returns 0 on success, nonzero on failure */
+int
+dmnsn_gl_write_canvas(const dmnsn_canvas *canvas)
+{
+ GLuint *pixels; /* Array of 32-bit ints in RGBA order */
+ GLuint *pixel;
+ dmnsn_sRGB sRGB;
+ dmnsn_color color;
+ unsigned int x, y, width, height;
+
+ width = canvas->x;
+ height = canvas->y;
+
+ pixels = malloc(4*width*height*sizeof(GLuint));
+ if (!pixels) {
+ return 1;
+ }
+
+ for (y = 0; y < height; ++y) {
+ for (x = 0; x < width; ++x) {
+ pixel = pixels + 4*(y*width + x);
+
+ color = dmnsn_get_pixel(canvas, x, y);
+ sRGB = dmnsn_sRGB_from_color(color);
+
+ /* Saturate R, G, and B to [0, UINT32_MAX] */
+
+ if (sRGB.R <= 0.0) {
+ pixel[0] = 0;
+ } else if (sRGB.R >= 1.0) {
+ pixel[0] = UINT32_MAX;
+ } else {
+ pixel[0] = sRGB.R*UINT32_MAX;
+ }
+
+ if (sRGB.G <= 0.0) {
+ pixel[1] = 0;
+ } else if (sRGB.G >= 1.0) {
+ pixel[1] = UINT32_MAX;
+ } else {
+ pixel[1] = sRGB.G*UINT32_MAX;
+ }
+
+ if (sRGB.B <= 0.0) {
+ pixel[2] = 0;
+ } else if (sRGB.B >= 1.0) {
+ pixel[2] = UINT32_MAX;
+ } else {
+ pixel[2] = sRGB.B*UINT32_MAX;
+ }
+
+ /* color.filter + color.trans is in [0.0, 1.0] by definition */
+ pixel[3] = (color.filter + color.trans)*UINT32_MAX;
+ }
+ }
+
+ glDrawPixels(width, height, GL_RGBA, GL_UNSIGNED_INT, pixels);
+
+ free(pixels);
+ return 0;
+}
+
+/* Read a canvas from a GL framebuffer. Returns NULL on failure. */
+dmnsn_canvas *
+dmnsn_gl_read_canvas()
+{
+ return NULL;
+}