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/* -*- mode: c; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; coding: utf-8-unix -*- */
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Copyright (c) 2010 Kristóf Ralovich
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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#include "shaderutil.h"
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static int WinWidth = 256, WinHeight = 256;
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static GLboolean mouseGrabbed = GL_FALSE;
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static GLuint vertShader;
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static GLuint program;
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float rot[9] = {1,0,0, 0,1,0, 0,0,1};
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static const char* vsSource =
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"const float INF = 9999.9; \n"
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"const float EPSILON = 0.00001; \n"
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"const vec3 lightPos = vec3(0.0, 8.0, 1.0); \n"
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"const vec4 backgroundColor = vec4(0.2,0.3,0.4,1); \n"
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"uniform mat3 rot; \n"
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"Sphere spheres0 = Sphere( vec3(0.0,0.0,-1.0), 0.5 ); \n"
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"Sphere spheres1 = Sphere( vec3(-3.0,0.0,-1.0), 1.5 ); \n"
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"Sphere spheres2 = Sphere( vec3(0.0,3.0,-1.0), 0.5 ); \n"
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"Sphere spheres3 = Sphere( vec3(2.0,0.0,-1.0), 1.0 ); \n"
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"const Sphere spheres0 = Sphere( vec3(0.0,0.0,-1.0), 0.5 ); \n"
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"const Sphere spheres1 = Sphere( vec3(-3.0,0.0,-1.0), 1.5 ); \n"
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"const Sphere spheres2 = Sphere( vec3(0.0,3.0,-1.0), 0.5 ); \n"
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"const Sphere spheres3 = Sphere( vec3(2.0,0.0,-1.0), 1.0 ); \n"
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"// Mesa intel gen4 generates \"unsupported IR in fragment shader 13\" for\n"
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"// sqrt, let's work around. \n"
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"sqrt_hack(float f2) \n"
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" vec3 v = vec3(f2,0.0,0.0); \n"
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" return length(v); \n"
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"intersect(const in Ray ray, \n"
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" const in Sphere sph, \n"
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" const in int idx, \n"
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" inout Isec isec) \n"
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" // Project both o and the sphere to the plane perpendicular to d \n"
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" // and containing c. Let x be the point where the ray intersects \n"
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" // the plane. If |x-c| < r, the ray intersects the sphere. \n"
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" vec3 o = ray.orig; \n"
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" vec3 d = ray.dir; \n"
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" vec3 c = sph.c; \n"
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" float r = sph.r; \n"
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" float t = dot(c-o,n)/dot(n,d); \n"
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" vec3 x = o+d*t; \n"
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" float e = length(x-c); \n"
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" // no intersection \n"
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" // Apply Pythagorean theorem on the (intersection,x,c) triangle \n"
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" // to get the distance between c and the intersection. \n"
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"#define BUGGY_INTEL_GEN4_GLSL 1 \n"
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"#ifndef BUGGY_INTEL_GEN4_GLSL \n"
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" float f = sqrt(r*r - e*e); \n"
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" float f = sqrt_hack(r*r - e*e); \n"
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" float dist = t - f; \n"
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" // inside the sphere \n"
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" if(dist < EPSILON) \n"
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" if(dist > isec.t) \n"
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" isec.idx = idx; \n"
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" isec.hit = ray.orig + ray.dir * isec.t; \n"
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" isec.n = (isec.hit - c) / r; \n"
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"intersect(const in Ray ray, \n"
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" const in float max_t /*= INF*/) \n"
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" nearest.t = max_t; \n"
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" nearest.idx = -1; \n"
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" intersect(ray, spheres0, 0, nearest); \n"
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" intersect(ray, spheres1, 1, nearest); \n"
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" intersect(ray, spheres2, 2, nearest); \n"
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" intersect(ray, spheres3, 3, nearest); \n"
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" return nearest; \n"
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"idx2color(const in int idx) \n"
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" diff = vec4(1.0, 0.0, 0.0, 0.0); \n"
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" else if(idx == 1) \n"
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" diff = vec4(0.0, 1.0, 0.0, 0.0); \n"
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" else if(idx == 2) \n"
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" diff = vec4(0.0, 0.0, 1.0, 0.0); \n"
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" else if(idx == 3) \n"
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" diff = vec4(1.0, 1.0, 0.0, 0.0); \n"
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"trace0(const in Ray ray) \n"
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" Isec isec = intersect(ray, INF); \n"
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" if(isec.idx == -1) \n"
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" return backgroundColor; \n"
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" vec4 diff = idx2color(isec.idx); \n"
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" vec3 N = isec.n; \n"
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" vec3 L = normalize(lightPos-isec.hit); \n"
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" vec3 camera_dir = normalize(ray.orig - isec.hit); \n"
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" return dot(N,L)*diff + pow( \n"
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" clamp(dot(reflect(-L,N),camera_dir),0.0,1.0),16.0); \n"
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"trace1(const in Ray ray) \n"
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" Isec isec = intersect(ray, INF); \n"
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" if(isec.idx == -1) \n"
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" return backgroundColor; \n"
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" Ray reflRay = Ray(isec.hit, reflect(ray.dir, isec.n)); \n"
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" vec4 reflCol = trace0(reflRay); \n"
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" vec4 diff = idx2color(isec.idx) + reflCol; \n"
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" vec3 N = isec.n; \n"
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" vec3 L = normalize(lightPos-isec.hit); \n"
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" vec3 camera_dir = normalize(ray.orig - isec.hit); \n"
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" return dot(N,L)*diff + pow( \n"
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" clamp(dot(reflect(-L,N),camera_dir),0.0,1.0),16.0); \n"
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" const vec3 cameraPos = vec3(0,0,3); \n"
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" vec3 rayDir = normalize(vec3(gl_Vertex.x, gl_Vertex.y, -1.0) * rot);\n"
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" Ray ray = Ray(cameraPos, rayDir); \n"
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" gl_Position = gl_Vertex; \n"
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" gl_FrontColor = trace1(ray); \n"
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deg2rad(const float degree)
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return( degree * 0.017453292519943295769236907684886F);
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rotate_xy(float* mat3, const float degreesAroundX, const float degreesAroundY)
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const float rad1 = deg2rad(degreesAroundX);
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const float c1 = cosf(rad1);
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const float s1 = sinf(rad1);
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const float rad2 = deg2rad(degreesAroundY);
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const float c2 = cosf(rad2);
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const float s2 = sinf(rad2);
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mat3[0] = c2; mat3[3] = 0.0F; mat3[6] = s2;
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mat3[1] = s1*s2; mat3[4] = c1; mat3[7] = -s1*c2;
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mat3[2] = -c1*s2;mat3[5] = s1; mat3[8] = c1*c2;
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identity(float* mat3)
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mat3[0] = 1.0F; mat3[3] = 0.0F; mat3[6] = 0.0F;
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mat3[1] = 0.0F; mat3[4] = 1.0F; mat3[7] = 0.0F;
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mat3[2] = 0.0F; mat3[5] = 0.0F; mat3[8] = 1.0F;
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const float w = 0.5F * WinWidth;
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const float h = 0.5F * WinHeight;
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GLint location = glGetUniformLocation(program, "rot");
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glUseProgram(program);
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glUniformMatrix3fv(location, 1, 0, rot);
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for(y = 0; y < WinHeight; y++)
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for(x = 0; x < WinWidth; x++)
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const float posx = x / w - 1.0F;
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const float posy = y / h - 1.0F;
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glVertex2f(posx, posy);
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static int frames = 0;
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t1 = glutGet(GLUT_ELAPSED_TIME);
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dt = (float)(t1-t0)/1000.0F;
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float fps = (float)frames / dt;
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printf("%f FPS (%d frames in %f seconds)\n", fps, frames, dt);
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Reshape(int width, int height)
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glViewport(0, 0, width, height);
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glMatrixMode(GL_PROJECTION);
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glMatrixMode(GL_MODELVIEW);
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Key(unsigned char key, int x, int y)
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glutDestroyWindow(Win);
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static GLfloat xRot = 0, yRot = 0;
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xRot = (float)(x - WinWidth/2) / scale;
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yRot = (float)(y - WinHeight/2) / scale;
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rotate_xy(rot, yRot, xRot);
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mouse(int button, int state, int x, int y)
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mouseGrabbed = (state == GLUT_DOWN);
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glDisable(GL_DEPTH_TEST);
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if(!ShadersSupported())
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fprintf(stderr, "Shaders are not supported!\n");
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vertShader = CompileShaderText(GL_VERTEX_SHADER, vsSource);
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program = LinkShaders(vertShader, 0);
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if(glGetError() != 0)
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fprintf(stderr, "Shaders were not loaded!\n");
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if(!glIsShader(vertShader))
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fprintf(stderr, "Vertex shader failed!\n");
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if(!glIsProgram(program))
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fprintf(stderr, "Shader program failed!\n");
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printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
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main(int argc, char *argv[])
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glutInitWindowSize(WinWidth, WinHeight);
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glutInit(&argc, argv);
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glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
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Win = glutCreateWindow(argv[0]);
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glutReshapeFunc(Reshape);
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glutKeyboardFunc(Key);
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glutDisplayFunc(Draw);
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glutMouseFunc(mouse);
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glutMotionFunc(drag);
added
removed
src/glsl/vsraytrace.c
