| /** |
| * Vertex "skinning" example. |
| * The idea is there are multiple modeling matrices applied to every |
| * vertex. Weighting values in [0,1] control the influence of each |
| * matrix on each vertex. |
| * |
| * 4 Nov 2008 |
| */ |
| |
| #include <assert.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <math.h> |
| #include <GL/glew.h> |
| #include <GL/glut.h> |
| #include "shaderutil.h" |
| |
| #ifndef M_PI |
| #define M_PI 3.1415926535 |
| #endif |
| |
| static char *FragProgFile = "skinning.frag"; |
| static char *VertProgFile = "skinning.vert"; |
| |
| /* program/shader objects */ |
| static GLuint fragShader; |
| static GLuint vertShader; |
| static GLuint program; |
| |
| |
| static GLint win = 0; |
| static GLboolean Anim = GL_TRUE; |
| static GLboolean WireFrame = GL_TRUE; |
| static GLfloat xRot = 0.0f, yRot = 90.0f, zRot = 0.0f; |
| |
| #define NUM_MATS 2 |
| |
| static GLfloat Matrices[NUM_MATS][16]; |
| static GLint uMat0, uMat1; |
| static GLint WeightAttr; |
| |
| |
| static void |
| Idle(void) |
| { |
| yRot = 90 + glutGet(GLUT_ELAPSED_TIME) * 0.005; |
| glutPostRedisplay(); |
| } |
| |
| |
| static void |
| Cylinder(GLfloat length, GLfloat radius, GLint slices, GLint stacks) |
| { |
| float dw = 1.0 / (stacks - 1); |
| float dz = length / stacks; |
| int i, j; |
| |
| for (j = 0; j < stacks; j++) { |
| float w0 = j * dw; |
| float z0 = j * dz; |
| |
| glBegin(GL_TRIANGLE_STRIP); |
| for (i = 0; i < slices; i++) { |
| float a = (float) i / (slices - 1) * M_PI * 2.0; |
| float x = radius * cos(a); |
| float y = radius * sin(a); |
| glVertexAttrib1f(WeightAttr, w0); |
| glNormal3f(x, y, 0.0); |
| glVertex3f(x, y, z0); |
| |
| glVertexAttrib1f(WeightAttr, w0 + dw); |
| glNormal3f(x, y, 0.0); |
| glVertex3f(x, y, z0 + dz); |
| } |
| glEnd(); |
| } |
| } |
| |
| |
| /** |
| * Update/animate the two matrices. One rotates, the other scales. |
| */ |
| static void |
| UpdateMatrices(void) |
| { |
| GLfloat t = glutGet(GLUT_ELAPSED_TIME) * 0.0025; |
| GLfloat scale = 0.5 * (1.1 + sin(0.5 * t)); |
| GLfloat rot = cos(t) * 90.0; |
| |
| glPushMatrix(); |
| glLoadIdentity(); |
| glScalef(1.0, scale, 1.0); |
| glGetFloatv(GL_MODELVIEW_MATRIX, Matrices[0]); |
| glPopMatrix(); |
| |
| glPushMatrix(); |
| glLoadIdentity(); |
| glRotatef(rot, 0, 0, 1); |
| glGetFloatv(GL_MODELVIEW_MATRIX, Matrices[1]); |
| glPopMatrix(); |
| } |
| |
| |
| static void |
| Redisplay(void) |
| { |
| UpdateMatrices(); |
| |
| glUniformMatrix4fv(uMat0, 1, GL_FALSE, Matrices[0]); |
| glUniformMatrix4fv(uMat1, 1, GL_FALSE, Matrices[1]); |
| |
| if (WireFrame) |
| glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); |
| else |
| glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); |
| |
| glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); |
| |
| glPushMatrix(); |
| glRotatef(xRot, 1.0f, 0.0f, 0.0f); |
| glRotatef(yRot, 0.0f, 1.0f, 0.0f); |
| glRotatef(zRot, 0.0f, 0.0f, 1.0f); |
| |
| glPushMatrix(); |
| glTranslatef(0, 0, -2.5); |
| Cylinder(5.0, 1.0, 10, 20); |
| glPopMatrix(); |
| |
| glPopMatrix(); |
| |
| glutSwapBuffers(); |
| } |
| |
| |
| 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); |
| } |
| |
| |
| static void |
| CleanUp(void) |
| { |
| glDeleteShader(fragShader); |
| glDeleteShader(vertShader); |
| glDeleteProgram(program); |
| glutDestroyWindow(win); |
| } |
| |
| |
| static void |
| Key(unsigned char key, int x, int y) |
| { |
| const GLfloat step = 2.0; |
| (void) x; |
| (void) y; |
| |
| switch(key) { |
| case 'a': |
| Anim = !Anim; |
| if (Anim) |
| glutIdleFunc(Idle); |
| else |
| glutIdleFunc(NULL); |
| break; |
| case 'w': |
| WireFrame = !WireFrame; |
| break; |
| case 'z': |
| zRot += step; |
| break; |
| case 'Z': |
| zRot -= step; |
| break; |
| case 27: |
| CleanUp(); |
| exit(0); |
| break; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| static void |
| SpecialKey(int key, int x, int y) |
| { |
| const GLfloat step = 2.0; |
| |
| (void) x; |
| (void) y; |
| |
| switch(key) { |
| case GLUT_KEY_UP: |
| xRot += step; |
| break; |
| case GLUT_KEY_DOWN: |
| xRot -= step; |
| break; |
| case GLUT_KEY_LEFT: |
| yRot -= step; |
| break; |
| case GLUT_KEY_RIGHT: |
| yRot += step; |
| break; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| |
| static void |
| Init(void) |
| { |
| if (!ShadersSupported()) |
| exit(1); |
| |
| vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile); |
| fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile); |
| program = LinkShaders(vertShader, fragShader); |
| |
| glUseProgram(program); |
| |
| uMat0 = glGetUniformLocation(program, "mat0"); |
| uMat1 = glGetUniformLocation(program, "mat1"); |
| |
| WeightAttr = glGetAttribLocation(program, "weight"); |
| |
| assert(glGetError() == 0); |
| |
| glClearColor(0.4f, 0.4f, 0.8f, 0.0f); |
| |
| glEnable(GL_DEPTH_TEST); |
| |
| glColor3f(1, 0, 0); |
| } |
| |
| |
| static void |
| ParseOptions(int argc, char *argv[]) |
| { |
| int i; |
| for (i = 1; i < argc; i++) { |
| if (strcmp(argv[i], "-fs") == 0) { |
| FragProgFile = argv[i+1]; |
| } |
| else if (strcmp(argv[i], "-vs") == 0) { |
| VertProgFile = argv[i+1]; |
| } |
| } |
| } |
| |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| glutInit(&argc, argv); |
| glutInitWindowSize(500, 500); |
| glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); |
| win = glutCreateWindow(argv[0]); |
| glewInit(); |
| glutReshapeFunc(Reshape); |
| glutKeyboardFunc(Key); |
| glutSpecialFunc(SpecialKey); |
| glutDisplayFunc(Redisplay); |
| ParseOptions(argc, argv); |
| Init(); |
| if (Anim) |
| glutIdleFunc(Idle); |
| glutMainLoop(); |
| return 0; |
| } |
| |