Philip Calderon CSE 520 Lab 3 Color Shader

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1 Philip Calderon CSE 520 Lab 3 Color Shader Summary: The purpose of lab 4 is to produce a pyramid tetrahedron that we are able to rotate it when clicked. Part 1: Color Tetrahedron Part 2: Rotation to show different colors

2 Code: ////////////////////////////////////////////////////////////////////////////////////////////////// //triangle.frag uniform vec4 color0; uniform vec4 color1; varying float weight; // from vertex shader void main(void) vec4 color = mix ( color0, color1, weight ); // vec4 color = color0 + color1; gl_fragcolor = color; // color ////////////////////////////////////////////////////////////////////////////////////////////////// // vertex attribute float vertexvalue; attribute float xrot; attribute float yrot; varying float weight; //pass from vertex shader to fragment shader void main(void) vec4 v4; v4 = gl_vertex; weight = vertexvalue; gl_position = gl_projectionmatrix * gl_modelviewmatrix * v4;

3 ////////////////////////////////////////////////////////////////////////////////////////////////// /* Philip Calderon Updated triangle.cpp */ #include <stdlib.h> #include <stdio.h> #include <string.h> #include <fcntl.h> #include <sys/types.h> #include <unistd.h> #define GLEW_STATIC 1 #include <GL/glew.h> #include <GL/glu.h> #include <GL/glut.h> #include <iostream> using namespace std; /* Global handles for the currently active program object, with its two shader objects */ static float xrot = 0.0, yrot = 0.0, zrot = 0.0; // Angles to rotate the tetrahedron. #define screenheight 500; GLuint programobject = 0; GLuint vertexshaderobject = 0; GLuint fragmentshaderobject = 0; static GLint win = 0; int readshadersource(char *filename, GLchar **shader ) // Allocate memory to hold the source of our shaders. FILE *fp; int count, pos, shadersize; fp = fopen( filename, "r"); if (!fp ) pos = (int) ftell ( fp ); fseek ( fp, 0, SEEK_END ); shadersize = ( int ) ftell ( fp ) - pos; fseek ( fp, 0, SEEK_SET ); //move to end //calculates file size //rewind to beginning if ( shadersize <= 0 ) printf("shader %s empty\n", filename);

4 *shader = (GLchar *) malloc( shadersize + 1); // Read the source code count = (int) fread(*shader, 1, shadersize, fp); (*shader)[count] = '\0'; if (ferror(fp)) count = 0; fclose(fp); return 1; void checkerror() char *infolog; int infolen, len; unsigned int shaders[2] = vertexshaderobject, fragmentshaderobject; char names[][50] = "Vertex shader", "Fragment shader"; for ( int i = 0; i < 2; i++ ) glgetshaderiv( shaders[i], GL_INFO_LOG_LENGTH, &infolen); if ( infolen > 0 ) infolog = (char *) malloc ( infolen + 1 ); glgetshaderinfolog ( shaders[i], infolen, &len, infolog ); printf("\n***** %s: %s\n", names[i], infolog ); delete infolog; // public int installshaders(const GLchar *vertex, const GLchar *fragment) GLint vertcompiled, fragcompiled; // status values GLint linked; // Create a vertex shader object and a fragment shader object vertexshaderobject = glcreateshader(gl_vertex_shader); fragmentshaderobject = glcreateshader(gl_fragment_shader); // Load source code strings into shaders, compile and link glshadersource(vertexshaderobject, 1, &vertex, NULL); glshadersource(fragmentshaderobject, 1, &fragment, NULL);

5 glcompileshader(vertexshaderobject); glgetshaderiv(vertexshaderobject, GL_COMPILE_STATUS, &vertcompiled); glcompileshader( fragmentshaderobject ); glgetshaderiv( fragmentshaderobject, GL_COMPILE_STATUS, &fragcompiled); checkerror(); printf("vertcompiled, fragcompiled: %d, %d\n", vertcompiled, fragcompiled); if (!vertcompiled!fragcompiled) // Create a program object and attach the two compiled shaders programobject = glcreateprogram(); glattachshader( programobject, vertexshaderobject); glattachshader( programobject, fragmentshaderobject); // Link the program object gllinkprogram(programobject); glgetprogramiv(programobject, GL_LINK_STATUS, &linked); printf("linked=%d\n"); if (!linked) // Install program object as part of current state gluseprogram(programobject); return 1; int init(void) const char *version; GLchar *VertexShaderSource, *FragmentShaderSource; int loadstatus = 0; version = (const char *) glgetstring(gl_version); if (version[0] < '2' version[1]!= '.') printf("this program requires OpenGL > 2.x, found %s\n", version); exit(1); printf("version=%s\n", version ); readshadersource((char *) "triangle.vert", &VertexShaderSource ); readshadersource( (char *) "triangle.frag", &FragmentShaderSource ); loadstatus = installshaders(vertexshadersource, FragmentShaderSource); char names[][20] = "color0", "color1"; int loc[2];

6 for ( int i = 0; i < 2; i++ ) loc[i] = glgetuniformlocation (programobject, names[i] ); if ( loc[i] < 0 ) cout << "No such name: " << names[i] << endl; gluniform4f ( loc[0], 1.0, 0.0, 0.0, 1 ); gluniform4f ( loc[1], 0.0, 1.0, 1.0, 1 ); return loadstatus; void dwpyramid() GLfloat vec[4]; int vertexvalueloc; vertexvalueloc = glgetattriblocation ( programobject, "vertexvalue" ); glbegin( GL_TRIANGLES ); glvertexattrib1f ( vertexvalueloc, 0.1 ); glvertex3f (0.0, 1.0, 0.0 ); glvertexattrib1f ( vertexvalueloc, 0.1 ); glvertex3f (-1.0, -1.0, 1.0 ); glvertexattrib1f ( vertexvalueloc, 0.1 ); glvertex3f ( 1.0, -1.0, 1.0 ); glvertexattrib1f ( vertexvalueloc, 0.4 ); glvertex3f (0.0, 1.0, 0.0 ); glvertexattrib1f ( vertexvalueloc, 0.4 ); glvertex3f (-1.0, -1.0, 1.0 ); glvertexattrib1f ( vertexvalueloc, 0.4 ); glvertex3f ( 0.0, -1.0, -1.0 ); glvertexattrib1f ( vertexvalueloc, 0.6 ); glvertex3f (0.0, 1.0, 0.0 ); glvertexattrib1f ( vertexvalueloc, 0.6 ); glvertex3f (0.0, -1.0, -1.0 ); glvertexattrib1f ( vertexvalueloc, 0.6 ); glvertex3f ( 1.0, -1.0, 1.0 ); glvertexattrib1f ( vertexvalueloc, 0.9 ); glvertex3f (-1.0, -1.0, 1.0 ); glvertexattrib1f ( vertexvalueloc, 0.9 ); glvertex3f (0.0, -1.0, -1.0 ); glvertexattrib1f ( vertexvalueloc, 0.9 ); glvertex3f ( 1.0, -1.0, 1.0 ); glend();

7 static void Reshape(int width, int height) glviewport(0, 0, width, height); glmatrixmode(gl_projection); glloadidentity(); glfrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0); glmatrixmode(gl_modelview); glloadidentity(); gltranslatef(0.0f, 0.0f, -15.0f); void display(void) GLfloat vec[4]; glclear(gl_color_buffer_bit GL_DEPTH_BUFFER_BIT); glclearcolor( 1.0, 1.0, 1.0, 1.0 ); //get white background color glcolor3f ( 0, 0, 1 ); //red, this will have no effect if shader is loaded glrotatef(xrot, 1.0f, 0.0f, 0.0f); glrotatef(yrot, 0.0f, 1.0f, 0.0f); dwpyramid(); glutswapbuffers(); glflush(); void CleanUp(void) gldeleteshader(vertexshaderobject); gldeleteshader(fragmentshaderobject); gldeleteprogram(programobject); glutdestroywindow(win); void mousemotion( int mousex, int mousey) GLint x = mousex; GLint y = screenheight - mousey; if (x) xrot += 5.0; if (xrot > 360.0) xrot -= 360.0; glutpostredisplay(); if (y) yrot += 5.0;

8 if (yrot > 360.0) yrot -= 360.0; glutpostredisplay(); glflush(); static void Key(unsigned char key, int x, int y) switch(key) case 27: CleanUp(); exit(0); break; glutpostredisplay(); int main(int argc, char *argv[]) int success = 0; glutinit(&argc, argv); glutinitwindowposition( 0, 0); glutinitwindowsize(500, 500); glutinitdisplaymode(glut_rgb GLUT_DOUBLE GLUT_DEPTH); win = glutcreatewindow("color Tetrahedron"); glutreshapefunc(reshape); glutkeyboardfunc(key); glutmotionfunc(mousemotion); glutdisplayfunc(display); // Initialize the "OpenGL Extension Wrangler" library glewinit(); success = init(); printf("success=%d\n", success ); if ( success ) glutmainloop(); Conclusion: The lab had us use a shader to color a pyramid that we had to create then have it rotate related to the mouse when clicked. There were no problems in any section in this lab 20/20.

1. Write a shader program that animates the morphing of Figure 'A' to Figure 'B' and back.

Karl Zachary Maier CSE 520 Homework 1 1. Write a shader program that animates the morphing of Figure 'A' to Figure 'B' and back. /* morph.cpp */ #include #include #include