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/*
THIS WORK, INCLUDING THE SOURCE CODE, DOCUMENTATION
AND RELATED MEDIA AND DATA, IS PLACED INTO THE PUBLIC DOMAIN.
THE ORIGINAL AUTHOR IS KYLE FOLEY.
THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
RESULTING FROM THE USE, MODIFICATION, OR
REDISTRIBUTION OF THIS SOFTWARE.
*/
#ifndef __EMSCRIPTEN__
#define USE_GLEW 1
#endif
#if USE_GLEW
#include "GL/glew.h"
#endif
#include "SDL/SDL.h"
#if !USE_GLEW
#include "SDL/SDL_opengl.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
void verify() {
int width = 640, height = 480;
unsigned char *data = (unsigned char*)malloc(width*height*4);
glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
int sum = 0;
for (int x = 0; x < width*height*4; x++) {
if (x % 4 != 3) sum += x * data[x];
}
}
int main(int argc, char *argv[])
{
SDL_Surface *screen;
if ( SDL_Init(SDL_INIT_VIDEO) != 0 ) {
printf("Unable to initialize SDL: %s\n", SDL_GetError());
return 1;
}
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
screen = SDL_SetVideoMode( 640, 480, 24, SDL_OPENGL );
if ( !screen ) {
printf("Unable to set video mode: %s\n", SDL_GetError());
return 1;
}
glClearColor( 0, 0, 0, 0 );
glClear( GL_COLOR_BUFFER_BIT );
// Create a texture
GLuint texture;
glGenTextures( 1, &texture );
glBindTexture( GL_TEXTURE_2D, texture );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
GLubyte textureData[16*16*4];
for (int x = 0; x < 16; x++) {
for (int y = 0; y < 16; y++) {
*((int*)&textureData[(x*16 + y) * 4]) = x*16 + ((y*16) << 8);
}
}
glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0,
GL_RGBA, GL_UNSIGNED_BYTE, textureData );
// Create a second texture
GLuint texture2;
glGenTextures( 1, &texture2 );
glBindTexture( GL_TEXTURE_2D, texture2 );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
GLubyte texture2Data[] = { 0xff, 0, 0, 0xff,
0, 0xff, 0, 0xaa,
0, 0, 0xff, 0x55,
0x80, 0x90, 0x70, 0 };
glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0,
GL_RGBA, GL_UNSIGNED_BYTE, texture2Data );
// BEGIN
#if USE_GLEW
glewInit();
#endif
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// original: glFrustum(-0.6435469817188064, 0.6435469817188064 ,-0.48266022190470925, 0.48266022190470925 ,0.5400000214576721, 2048);
glFrustum(-0.6435469817188064, 0.1435469817188064 ,-0.48266022190470925, 0.88266022190470925 ,0.5400000214576721, 2048);
glRotatef(-30, 1, 1, 1);
//GLfloat pm[] = { 1.372136116027832, 0, 0, 0, 0, 0.7910231351852417, 0, 0, -0.6352481842041016, 0.29297152161598206, -1.0005275011062622, -1, 0, 0, -1.080284833908081, 0 };
//glLoadMatrixf(pm);
glMatrixMode(GL_MODELVIEW);
GLfloat matrixData[] = { -1, 0, 0, 0,
0, 0,-1, 0,
0, 1, 0, 0,
0, 0, 0, 1 };
glLoadMatrixf(matrixData);
//glTranslated(-512,-512,-527); // XXX this should be uncommented, but if it is then nothing is shown
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
glClear(GL_DEPTH_BUFFER_BIT);
glEnableClientState(GL_NORMAL_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glActiveTexture(GL_TEXTURE0);
glEnableClientState(GL_VERTEX_ARRAY);
GLuint arrayBuffer, elementBuffer;
glGenBuffers(1, &arrayBuffer);
glGenBuffers(1, &elementBuffer);
GLubyte arrayData[] = {
/*
[0, 0, 0, 67] ==> 128 float
[0, 0, 128, 67] ==> 256 float
[0, 0, 0, 68] ==> 512 float
[0, 0, 128, 68] ==> 1024 float
[vertex x ] [vertex y ] [vertex z ] [nr] [texture u ] [texture v ] [lm u ] [lm v ] [color r,g,b,a ] */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 128, 255, 128, // 0
0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 0, 0, 0, 0, 0, 128, 0, 255, 128, // 1
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 67, 0, 0, 0, 0, 128, 64, 255, 128, // 2
0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 0, 128, 128, 255, 255, // 3
0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 0, 0, 0, 0, 0, 196, 128, 255, 128, // 4
0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 128, 67, 0, 0, 0, 0, 0, 0, 0, 0, 128, 0, 255, 128, // 5
0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 128, 67, 0, 0, 0, 67, 0, 0, 0, 0, 128, 128, 255, 128, // 6
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 67, 0, 0, 0, 0, 128, 64, 255, 0, // 7
0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 0, 64, 128, 255, 128, // 8
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 67, 0, 0, 0, 0, 128, 0, 255, 128, // 9
0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 128, 67, 0, 0, 0, 0, 128, 128, 255, 128, // 10
0, 0, 0, 0, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 67, 0, 0, 0, 0, 128, 128, 255, 0, // 11
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 0, 67, 0, 0, 0, 0, 100, 128, 255, 128, // 12
0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 128, 67, 0, 0, 0, 67, 0, 0, 0, 0, 128, 0, 255, 128, // 13
0, 0, 128, 68, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 128, 67, 0, 0, 128, 67, 0, 0, 0, 0, 128, 128, 255, 128, // 14
0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 67, 0, 0, 128, 67, 0, 0, 0, 0, 128, 128, 255, 0, // 15
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 0, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 0, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 128, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128,
0, 0, 128, 68, 0, 0, 128, 68, 0, 0, 0, 68, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128
};
assert(sizeof(arrayData) == 1408);
glBindBuffer(GL_ARRAY_BUFFER, arrayBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(arrayData), arrayData, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
GLushort elementData[] = { 1, 2, 0, 2, 3, 0, 5, 6, 4, 6, 7, 4, 9, 10, 8, 10, 11, 8, 13, 14, 12, 14, 15, 12 };
assert(sizeof(elementData) == 48);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(elementData), elementData, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
glBindBuffer(GL_ARRAY_BUFFER, arrayBuffer);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementBuffer);
// sauer vertex data is apparently 0-12: V3F, 12: N1B, 16-24: T2F, 24-28: T2S, 28-32: C4B
glVertexPointer(3, GL_FLOAT, 32, (void*)0); // all these apply to the ARRAY_BUFFER that is bound
glTexCoordPointer(2, GL_FLOAT, 32, (void*)16);
glClientActiveTexture(GL_TEXTURE1); // XXX seems to be ignored in native build
glTexCoordPointer(2, GL_SHORT, 32, (void*)24);
glClientActiveTexture(GL_TEXTURE0); // likely not needed, it is a cleanup
glNormalPointer(GL_BYTE, 32, (void*)12);
glColorPointer(4, GL_UNSIGNED_BYTE, 32, (void*)28);
glBindTexture(GL_TEXTURE_2D, texture); // diffuse?
glActiveTexture(GL_TEXTURE0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texture2); // lightmap?
glActiveTexture(GL_TEXTURE0);
GLint ok;
const char *vertexShader = "uniform vec4 texgenscroll;\n"
"void main(void)\n"
"{\n"
" gl_Position = ftransform();\n"
" gl_TexCoord[0].xy = gl_MultiTexCoord0.xy/100.0 + texgenscroll.xy;\n" // added /100 here
" gl_TexCoord[1] = gl_Color;\n"
"}\n";
const char *fragmentShader = "uniform vec4 colorparams;\n"
"uniform sampler2D diffusemap, lightmap;\n"
"void main(void)\n"
"{\n"
" vec4 diffuse = texture2D(diffusemap, gl_TexCoord[0].xy);\n"
" vec4 lm = texture2D(lightmap, gl_TexCoord[1].xy);\n"
" diffuse *= colorparams;\n"
" gl_FragColor = (diffuse * lm * 0.2) + gl_TexCoord[1];\n"
"}\n";
GLuint vs = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vs, 1, &vertexShader, NULL);
glCompileShader(vs);
glGetShaderiv(vs, GL_COMPILE_STATUS, &ok);
assert(ok);
GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fs, 1, &fragmentShader, NULL);
glCompileShader(fs);
glGetShaderiv(fs, GL_COMPILE_STATUS, &ok);
assert(ok);
GLuint program = glCreateProgram();
glAttachShader(program, vs);
glAttachShader(program, fs);
glLinkProgram(program);
glGetProgramiv(program, GL_LINK_STATUS, &ok);
assert(ok);
glUseProgram(program);
GLint lightmapLocation = glGetUniformLocation(program, "lightmap");
assert(lightmapLocation >= 0);
glUniform1i(lightmapLocation, 1); // sampler2D? Is it the texture unit?
GLint diffusemapLocation = glGetUniformLocation(program, "diffusemap");
assert(diffusemapLocation >= 0);
glUniform1i(diffusemapLocation, 0);
GLint texgenscrollLocation = glGetUniformLocation(program, "texgenscroll");
assert(texgenscrollLocation >= 0);
GLint colorparamsLocation = glGetUniformLocation(program, "colorparams");
assert(colorparamsLocation >= 0);
GLfloat texgenscrollData[] = { 0, 0, 0, 0 };
glUniform4fv(texgenscrollLocation, 1, texgenscrollData);
GLfloat colorparamsData[] = { 2, 2, 2, 1 };
glUniform4fv(colorparamsLocation, 1, colorparamsData);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (void*)12);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (void*) 0);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (void*)24);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (void*)36);
// END
SDL_GL_SwapBuffers();
verify();
#ifndef __EMSCRIPTEN__
SDL_Delay(1500);
#endif
SDL_Quit();
return 0;
}
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