| 1 | /* |
| 2 | * Copyright (c) 2012 Carsten Munk <carsten.munk@gmail.com> |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | * |
| 16 | */ |
| 17 | |
| 18 | #include <EGL/egl.h> |
| 19 | #include <GLES2/gl2.h> |
| 20 | #include <assert.h> |
| 21 | #include <stdio.h> |
| 22 | #include <math.h> |
| 23 | #include <stddef.h> |
| 24 | |
| 25 | const char vertex_src [] = |
| 26 | " \ |
| 27 | attribute vec4 position; \ |
| 28 | varying mediump vec2 pos; \ |
| 29 | uniform vec4 offset; \ |
| 30 | \ |
| 31 | void main() \ |
| 32 | { \ |
| 33 | gl_Position = position + offset; \ |
| 34 | pos = position.xy; \ |
| 35 | } \ |
| 36 | "; |
| 37 | |
| 38 | |
| 39 | const char fragment_src [] = |
| 40 | " \ |
| 41 | varying mediump vec2 pos; \ |
| 42 | uniform mediump float phase; \ |
| 43 | \ |
| 44 | void main() \ |
| 45 | { \ |
| 46 | gl_FragColor = vec4( 1., 0.9, 0.7, 1.0 ) * \ |
| 47 | cos( 30.*sqrt(pos.x*pos.x + 1.5*pos.y*pos.y) \ |
| 48 | + atan(pos.y,pos.x) - phase ); \ |
| 49 | } \ |
| 50 | "; |
| 51 | |
| 52 | GLuint load_shader(const char *shader_source, GLenum type) |
| 53 | { |
| 54 | GLuint shader = glCreateShader(type); |
| 55 | |
| 56 | glShaderSource(shader, 1, &shader_source, NULL); |
| 57 | glCompileShader(shader); |
| 58 | |
| 59 | return shader; |
| 60 | } |
| 61 | |
| 62 | |
| 63 | GLfloat norm_x = 0.0; |
| 64 | GLfloat norm_y = 0.0; |
| 65 | GLfloat offset_x = 0.0; |
| 66 | GLfloat offset_y = 0.0; |
| 67 | GLfloat p1_pos_x = 0.0; |
| 68 | GLfloat p1_pos_y = 0.0; |
| 69 | |
| 70 | GLint phase_loc; |
| 71 | GLint offset_loc; |
| 72 | GLint position_loc; |
| 73 | |
| 74 | const float vertexArray[] = { |
| 75 | 0.0, 1.0, 0.0, |
| 76 | -1., 0.0, 0.0, |
| 77 | 0.0, -1.0, 0.0, |
| 78 | 1., 0.0, 0.0, |
| 79 | 0.0, 1., 0.0 |
| 80 | }; |
| 81 | |
| 82 | |
| 83 | int main(int argc, char **argv) |
| 84 | { |
| 85 | EGLDisplay display; |
| 86 | EGLConfig ecfg; |
| 87 | EGLint num_config; |
| 88 | EGLint attr[] = { // some attributes to set up our egl-interface |
| 89 | EGL_BUFFER_SIZE, 32, |
| 90 | EGL_RENDERABLE_TYPE, |
| 91 | EGL_OPENGL_ES2_BIT, |
| 92 | EGL_NONE |
| 93 | }; |
| 94 | EGLSurface surface; |
| 95 | EGLint ctxattr[] = { |
| 96 | EGL_CONTEXT_CLIENT_VERSION, 2, |
| 97 | EGL_NONE |
| 98 | }; |
| 99 | EGLContext context; |
| 100 | |
| 101 | EGLBoolean rv; |
| 102 | |
| 103 | display = eglGetDisplay(NULL); |
| 104 | assert(eglGetError() == EGL_SUCCESS); |
| 105 | assert(display != EGL_NO_DISPLAY); |
| 106 | |
| 107 | rv = eglInitialize(display, 0, 0); |
| 108 | assert(eglGetError() == EGL_SUCCESS); |
| 109 | assert(rv == EGL_TRUE); |
| 110 | |
| 111 | eglChooseConfig((EGLDisplay) display, attr, &ecfg, 1, &num_config); |
| 112 | assert(eglGetError() == EGL_SUCCESS); |
| 113 | assert(rv == EGL_TRUE); |
| 114 | |
| 115 | surface = eglCreateWindowSurface((EGLDisplay) display, ecfg, (EGLNativeWindowType)NULL, NULL); |
| 116 | assert(eglGetError() == EGL_SUCCESS); |
| 117 | assert(surface != EGL_NO_SURFACE); |
| 118 | |
| 119 | context = eglCreateContext((EGLDisplay) display, ecfg, EGL_NO_CONTEXT, ctxattr); |
| 120 | assert(eglGetError() == EGL_SUCCESS); |
| 121 | assert(context != EGL_NO_CONTEXT); |
| 122 | |
| 123 | assert(eglMakeCurrent((EGLDisplay) display, surface, surface, context) == EGL_TRUE); |
| 124 | |
| 125 | const char *version = (const char *)glGetString(GL_VERSION); |
| 126 | assert(version); |
| 127 | printf("%s\n",version); |
| 128 | |
| 129 | |
| 130 | GLuint vertexShader = load_shader ( vertex_src , GL_VERTEX_SHADER ); // load vertex shader |
| 131 | GLuint fragmentShader = load_shader ( fragment_src , GL_FRAGMENT_SHADER ); // load fragment shader |
| 132 | |
| 133 | GLuint shaderProgram = glCreateProgram (); // create program object |
| 134 | glAttachShader ( shaderProgram, vertexShader ); // and attach both... |
| 135 | glAttachShader ( shaderProgram, fragmentShader ); // ... shaders to it |
| 136 | |
| 137 | glLinkProgram ( shaderProgram ); // link the program |
| 138 | glUseProgram ( shaderProgram ); // and select it for usage |
| 139 | |
| 140 | //// now get the locations (kind of handle) of the shaders variables |
| 141 | position_loc = glGetAttribLocation ( shaderProgram , "position" ); |
| 142 | phase_loc = glGetUniformLocation ( shaderProgram , "phase" ); |
| 143 | offset_loc = glGetUniformLocation ( shaderProgram , "offset" ); |
| 144 | if ( position_loc < 0 || phase_loc < 0 || offset_loc < 0 ) { |
| 145 | return 1; |
| 146 | } |
| 147 | |
| 148 | //glViewport ( 0 , 0 , 800, 600); // commented out so it uses the initial window dimensions |
| 149 | glClearColor ( 1. , 1. , 1. , 1.); // background color |
| 150 | float phase = 0; |
| 151 | int i; |
| 152 | for (i=0; i<3*60; ++i) { |
| 153 | glClear(GL_COLOR_BUFFER_BIT); |
| 154 | glUniform1f ( phase_loc , phase ); // write the value of phase to the shaders phase |
| 155 | phase = fmodf ( phase + 0.5f , 2.f * 3.141f ); // and update the local variable |
| 156 | |
| 157 | glUniform4f ( offset_loc , offset_x , offset_y , 0.0 , 0.0 ); |
| 158 | |
| 159 | glVertexAttribPointer ( position_loc, 3, GL_FLOAT, GL_FALSE, 0, vertexArray ); |
| 160 | glEnableVertexAttribArray ( position_loc ); |
| 161 | glDrawArrays ( GL_TRIANGLE_STRIP, 0, 5 ); |
| 162 | |
| 163 | eglSwapBuffers ( (EGLDisplay) display, surface ); // get the rendered buffer to the screen |
| 164 | } |
| 165 | |
| 166 | printf("stop\n"); |
| 167 | |
| 168 | #if 0 |
| 169 | (*egldestroycontext)((EGLDisplay) display, context); |
| 170 | printf("destroyed context\n"); |
| 171 | |
| 172 | (*egldestroysurface)((EGLDisplay) display, surface); |
| 173 | printf("destroyed surface\n"); |
| 174 | (*eglterminate)((EGLDisplay) display); |
| 175 | printf("terminated\n"); |
| 176 | android_dlclose(baz); |
| 177 | #endif |
| 178 | } |
| 179 | |
| 180 | // vim:ts=4:sw=4:noexpandtab |