123 строки
3.6 KiB
C
123 строки
3.6 KiB
C
//========================================================================
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// This is an example program for the GLFW library
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//
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// It shows texture loading with mipmap generation and rendering with
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// trilienar texture filtering
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//========================================================================
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#include <stdio.h>
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#include <stdlib.h>
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#include <GL/glfw.h>
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int main( void )
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{
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int width, height, x;
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double time;
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GLboolean running;
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GLuint textureID;
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char* texturePath = "mipmaps.tga";
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// Initialise GLFW
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if( !glfwInit() )
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{
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fprintf( stderr, "Failed to initialize GLFW\n" );
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exit( EXIT_FAILURE );
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}
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// Open OpenGL window
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if( !glfwOpenWindow( 640, 480, 0,0,0,0, 0,0, GLFW_WINDOW ) )
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{
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fprintf( stderr, "Failed to open GLFW window\n" );
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glfwTerminate();
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exit( EXIT_FAILURE );
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}
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glfwSetWindowTitle( "Trilinear interpolation" );
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// Enable sticky keys
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glfwEnable( GLFW_STICKY_KEYS );
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// Enable vertical sync (on cards that support it)
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glfwSwapInterval( 1 );
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// Generate and bind our texture ID
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glGenTextures( 1, &textureID );
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glBindTexture( GL_TEXTURE_2D, textureID );
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// Load texture from file into video memory, including mipmap levels
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if( !glfwLoadTexture2D( texturePath, GLFW_BUILD_MIPMAPS_BIT ) )
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{
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fprintf( stderr, "Failed to load texture %s\n", texturePath );
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glfwTerminate();
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exit( EXIT_FAILURE );
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}
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// Use trilinear interpolation (GL_LINEAR_MIPMAP_LINEAR)
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glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
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GL_LINEAR_MIPMAP_LINEAR );
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glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
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GL_LINEAR );
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// Enable plain 2D texturing
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glEnable( GL_TEXTURE_2D );
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running = GL_TRUE;
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while( running )
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{
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// Get time and mouse position
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time = glfwGetTime();
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glfwGetMousePos( &x, NULL );
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// Get window size (may be different than the requested size)
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glfwGetWindowSize( &width, &height );
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height = height > 0 ? height : 1;
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// Set viewport
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glViewport( 0, 0, width, height );
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// Clear color buffer
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glClearColor( 0.0f, 0.0f, 0.0f, 0.0f);
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glClear( GL_COLOR_BUFFER_BIT );
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// Select and setup the projection matrix
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glMatrixMode( GL_PROJECTION );
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glLoadIdentity();
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gluPerspective( 65.0f, (GLfloat)width / (GLfloat)height, 1.0f,
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50.0f );
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// Select and setup the modelview matrix
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glMatrixMode( GL_MODELVIEW );
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glLoadIdentity();
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gluLookAt( 0.0f, 3.0f, -20.0f, // Eye-position
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0.0f, -4.0f, -11.0f, // View-point
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0.0f, 1.0f, 0.0f ); // Up-vector
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// Draw a textured quad
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glRotatef( 0.05f * (GLfloat)x + (GLfloat)time * 5.0f, 0.0f, 1.0f, 0.0f );
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glBegin( GL_QUADS );
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glTexCoord2f( -20.0f, 20.0f );
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glVertex3f( -50.0f, 0.0f, -50.0f );
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glTexCoord2f( 20.0f, 20.0f );
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glVertex3f( 50.0f, 0.0f, -50.0f );
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glTexCoord2f( 20.0f, -20.0f );
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glVertex3f( 50.0f, 0.0f, 50.0f );
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glTexCoord2f( -20.0f, -20.0f );
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glVertex3f( -50.0f, 0.0f, 50.0f );
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glEnd();
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// Swap buffers
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glfwSwapBuffers();
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// Check if the ESC key was pressed or the window was closed
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running = !glfwGetKey( GLFW_KEY_ESC ) &&
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glfwGetWindowParam( GLFW_OPENED );
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}
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// Close OpenGL window and terminate GLFW
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glfwTerminate();
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exit( EXIT_SUCCESS );
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}
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