1)Write a shader program that renders a regular pentagon with textured image like the one shown below.

Size: px

Start display at page:

Download "1)Write a shader program that renders a regular pentagon with textured image like the one shown below."

Florence Stanley
6 years ago
Views:

1 Andrew Yenalavitch CSE520 Winter 2015 Quiz 2 Report 1)Write a shader program that renders a regular pentagon with textured image like the one shown below.

Use the following provided image for the texture: 2) Pass a time parameter from the C/C++ application to the shader program so that the textured image shrinks and expands periodically 3) Add in your

2 Use the following provided image for the texture: 2) Pass a time parameter from the C/C++ application to the shader program so that the textured image shrinks and expands periodically 3) Add in your C/C++ application or your shader program a feature so that when a user presses the key 'z', the textured image will be rotated by 3 o in the anti-clockwise direction about the z-axis; when 'Z' is pressed, it rotates in the clockwise direction.

3 My output for problem 1: My output for problem 2:

My output for problem 3: For problem 1, I started with the simpletex.cpp file from lab 9 and modified the number of sides of the gludisk to 5 to create a pentagon.

4 My output for problem 3: For problem 1, I started with the simpletex.cpp file from lab 9 and modified the number of sides of the gludisk to 5 to create a pentagon. gludisk(qobj, 0, 1, 5, 10); Then for problem 2, I added elements from homework 2, #1. These were added to simpletex.cpp: GLuint timeparam; timeparam = glgetuniformlocation ( programobject, "time" ); static void Idle(void) gluniform1f( timeparam, glutget ( GLUT_ELAPSED_TIME ) ); glutpostredisplay();

5 And the following was added/changed in simpletex.vert uniform float time; // global variable float r = 0; r = r * sin ( * time ); if (r < 0) r = 0; if (r > 1) r = 1; mat4 ScalarMatrix = mat4( r, 0.0, 0.0, 0.0, 0.0, r, 0.0, 0.0, 0.0, 0.0, r, 0.0, 0.0, 0.0, 0.0, 1.0 ); gl_position = gl_modelviewprojectionmatrix * ScalarMatrix * gl_vertex; And for problem 3, I added rotation controls via the Key function: int anglez = 0; // global variable glrotatef( anglez, 0.0, 0.0, 1.0); //in display static void Key(unsigned char key, int x, int y) case 'z': anglez = ( anglez + 3 ) % 360; break; case 'Z': anglez = ( anglez - 3 ) % 360; break;

6 glutpostredisplay(); Full source code: //simpletex.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 "imageio.h" using namespace std; /* Global handles for the currently active program object, with its two shader objects */ GLuint programobject = 0; GLuint vertexshaderobject = 0; GLuint fragmentshaderobject = 0; static GLint win = 0; GLuint timeparam; int anglez = 0; //rotation angle

7 int objecttype = 0; GLuint texname; int iwidth = 64, iheight = 64; /* static GLubyte checkimage[iheight][iwidth][3]; void makecheckimage(void) int i, j, c; for (i = 0; i < iwidth; i++) for (j = 0; j < iheight; j++) c = ((((i&0x8)==0)^((j&0x8))==0))*255; checkimage[i][j][0] = (GLubyte) c; checkimage[i][j][1] = (GLubyte) c; checkimage[i][j][2] = (GLubyte) c; */ GLubyte* maketeximage( char *loadfile ) int i, j, c, width, height; GLubyte *teximage; teximage = loadimagergba( (char *) loadfile, &width, &height); iwidth = width; iheight = height; return teximage; void init2dtexture()

8 // makecheckimage(); char filename[100]; printf("enter png file name: "); scanf ("%s", filename ); //GLubyte *teximage = maketeximage( "front.png" ); GLubyte *teximage = maketeximage( filename ); if (!teximage ) printf("\nerror reading %s \n", filename ); exit(1); glgentextures(1, &texname); glbindtexture(gl_texture_2d, texname); //now we work on texname gltexparameteri(gl_texture_2d, GL_TEXTURE_WRAP_S, GL_REPEAT); gltexparameteri(gl_texture_2d, GL_TEXTURE_WRAP_T, GL_REPEAT); gltexparameteri(gl_texture_2d, GL_TEXTURE_MAG_FILTER, GL_LINEAR); gltexparameteri(gl_texture_2d, GL_TEXTURE_MIN_FILTER, GL_LINEAR); // glteximage2d(gl_texture_2d, 0, GL_RGB, iwidth, // iheight, 0, GL_RGB, GL_UNSIGNED_BYTE, checkimage ); glteximage2d( GL_TEXTURE_2D, 0, GL_RGBA, iwidth, iheight, 0, GL_RGBA, GL_UNSIGNED_BYTE, teximage); delete teximage; 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 )

9 return 0; 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); return 0; *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; // public int installshaders(const GLchar *vertex, const GLchar *fragment) GLint vertcompiled, fragcompiled; // status values GLint linked;

10 // 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); glcompileshader(vertexshaderobject); glgetshaderiv(vertexshaderobject, GL_COMPILE_STATUS, &vertcompiled); glcompileshader( fragmentshaderobject ); glgetshaderiv( fragmentshaderobject, GL_COMPILE_STATUS, &fragcompiled); if (!vertcompiled!fragcompiled) return 0; // 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); if (!linked) return 0; // Install program object as part of current state

11 gluseprogram(programobject); // Set up initial uniform values gluniform3f(glgetuniformlocation(programobject, "LightPosition"), 2.0, 2.0, 4.0); gluniform1i(glgetuniformlocation(programobject, "texhandle"), 0); 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); gldepthfunc(gl_less); glenable(gl_depth_test); glclearcolor(1.0f, 1.0f, 1.0f, 1.0f); readshadersource("simpletex.vert", &VertexShaderSource ); readshadersource("simpletex.frag", &FragmentShaderSource ); loadstatus = installshaders(vertexshadersource, FragmentShaderSource); timeparam = glgetuniformlocation ( programobject, "time" ); init2dtexture();

12 return loadstatus; static void Reshape(int w, int h) float vp = 0.8f; float aspect = (float) w / (float) h; glviewport(0, 0, w, h); glmatrixmode(gl_projection); glloadidentity(); glviewport(0, 0, w, h); glmatrixmode(gl_projection); glloadidentity(); // glortho(-1.0, 1.0, -1.0, 1.0, -10.0, 10.0); glfrustum(-vp, vp, -vp / aspect, vp / aspect, 3, 10.0); glmatrixmode(gl_modelview); glloadidentity(); gltranslatef(0.0, 0.0, -5.0); void CleanUp(void) gldeleteshader(vertexshaderobject); gldeleteshader(fragmentshaderobject); gldeleteprogram(programobject); glutdestroywindow(win); static void Idle(void)

13 gluniform1f( timeparam, glutget ( GLUT_ELAPSED_TIME ) ); glutpostredisplay(); static void Key(unsigned char key, int x, int y) switch(key) case 27: CleanUp(); exit(0); break; case 'z': anglez = ( anglez + 3 ) % 360; break; case 'Z': anglez = ( anglez - 3 ) % 360; break; glutpostredisplay(); void display(void) GLfloat vec[4]; glclear(gl_color_buffer_bit GL_DEPTH_BUFFER_BIT); glclearcolor( 1.0, 1.0, 1.0, 0.0 ); //get white background color glpushmatrix(); glrotatef( anglez, 0.0, 0.0, 1.0); //rotate along z-axis glactivetexture(gl_texture0); glbindtexture(gl_texture_2d, texname); GLUquadric *qobj = glunewquadric();

14 // glutsolidsphere(), glutsolidtorus() do NOT have texture coordinates gluquadrictexture(qobj,gl_true); gludisk(qobj, 0, 1, 5, 10); glpopmatrix(); glutswapbuffers(); glflush(); 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(argv[0]); glutreshapefunc(reshape); glutkeyboardfunc(key); glutdisplayfunc(display); glutidlefunc(idle); // Initialize the "OpenGL Extension Wrangler" library glewinit(); success = init(); if ( success ) glutmainloop(); return 0; //simpletex.vert

15 uniform float time; varying float LightIntensity; uniform vec3 LightPosition; const float specularcontribution = 0.1; const float diffusecontribution = specularcontribution; void main(void) vec3 ecposition = vec3 (gl_modelviewmatrix * gl_vertex); vec3 tnorm = normalize(gl_normalmatrix * gl_normal); vec3 lightvec = normalize(lightposition - ecposition); vec3 reflectvec = reflect(-lightvec, tnorm); vec3 viewvec = normalize(-ecposition); float spec = clamp(dot(reflectvec, viewvec), 0.0, 1.0); spec = pow(spec, 16.0); LightIntensity = diffusecontribution * max(dot(lightvec, tnorm), 0.0) + specularcontribution * spec; float r = 0; r = r * sin ( * time ); if (r < 0) r = 0; if (r > 1) r = 1; mat4 ScalarMatrix = mat4( r, 0.0, 0.0, 0.0, 0.0, r, 0.0, 0.0, 0.0, 0.0, r, 0.0,

16 ); 0.0, 0.0, 0.0, 1.0 gl_position = gl_modelviewprojectionmatrix * ScalarMatrix * gl_vertex; gl_texcoord[0] = gl_multitexcoord0; //simpletex.frag varying float LightIntensity; uniform sampler2d texhandle; void main (void) vec3 lightcolor = vec3 (texture2d(texhandle, gl_texcoord[0].st)); gl_fragcolor = vec4 (lightcolor * LightIntensity, 1.0); Evaluation:I successfully completed all parts of the quiz and am giving myself 100 points.

1) Here is the various stages of the tetrahedron:

1) Here is the various stages of the tetrahedron: Andrew Yenalavitch Homework 3 CSE 520 - Winter 2015 1) ( 20 points ) Write a shader program that renders a colored tetrahedron, which gradually shrinks to a point and expands back to its original shape.