GLdc/samples/paletted_pcx/main.c
2019-03-07 21:21:30 +00:00

272 lines
9.0 KiB
C

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <assert.h>
#include "gl.h"
#include "glext.h"
#include "glu.h"
#include "glkos.h"
extern uint8 romdisk[];
KOS_INIT_ROMDISK(romdisk);
/* floats for x rotation, y rotation, z rotation */
float xrot, yrot, zrot;
/* storage for one texture */
int texture[1];
typedef struct {
unsigned int height;
unsigned int width;
unsigned int palette_width;
char* palette;
char* data;
} Image;
#pragma pack(push)
#pragma pack(1)
/* PCX header */
typedef struct {
uint8_t manufacturer;
uint8_t version;
uint8_t encoding;
uint8_t bits_per_pixel;
uint16_t xmin, ymin;
uint16_t xmax, ymax;
uint16_t horz_res, vert_res;
uint8_t palette[48];
uint8_t reserved;
uint8_t num_color_planes;
uint16_t bytes_per_scan_line;
uint16_t palette_type;
uint16_t horz_size, vert_size;
uint8_t padding[54];
} Header;
#pragma pack(pop)
int LoadPalettedPCX(const char* filename, Image* image) {
FILE* filein = NULL;
filein = fopen(filename, "rb");
if(!filein) {
printf("Unable to open file\n");
return 0;
}
Header header;
fread(&header, sizeof(header), 1, filein);
if(header.manufacturer != 0x0a) {
printf("Invalid file\n");
return 0;
}
/* Read the rest of the file */
long pos = ftell(filein);
fseek(filein, 0, SEEK_END);
long end = ftell(filein);
fseek(filein, pos, SEEK_SET);
long size = end - pos;
uint8_t* buffer = (uint8_t*) malloc(size);
fread(buffer, 1, size, filein);
image->width = header.xmax - header.xmin + 1;
image->height = header.ymax - header.ymin + 1;
image->data = (char*) malloc(sizeof(char) * image->width * image->height);
int bitcount = header.bits_per_pixel * header.num_color_planes;
if(bitcount != 8) {
printf("Wrong bitcount\n");
return 0;
}
uint8_t palette_marker = buffer[size - 769];
const uint8_t* palette = (palette_marker == 12) ? &buffer[size - 768] : header.palette;
image->palette_width = (palette_marker == 12) ? 256 : 16;
image->palette = (char*) malloc(sizeof(char) * 3 * image->palette_width);
memcpy(image->palette, palette, sizeof(char) * 3 * image->palette_width);
int32_t rle_count = 0;
int32_t rle_value = 0;
const uint8_t* image_data = buffer;
uint32_t idx;
for(idx = 0; idx < (image->width * image->height); idx++) {
if(rle_count == 0) {
rle_value = *image_data;
++image_data;
if((rle_value & 0xc0) == 0xc0) {
rle_count = rle_value & 0x3f;
rle_value = *image_data;
++image_data;
} else {
rle_count = 1;
}
}
rle_count--;
assert(rle_value < 256);
image->data[idx] = rle_value;
}
free(buffer);
return 1;
}
// Load Bitmaps And Convert To Textures
void LoadGLTextures() {
// Load Texture
Image *image1;
// allocate space for texture
image1 = (Image *) malloc(sizeof(Image));
if (image1 == NULL) {
printf("Error allocating space for image");
exit(0);
}
if (!LoadPalettedPCX("/rd/NeHe.pcx", image1)) {
exit(1);
}
glEnable(GL_SHARED_TEXTURE_PALETTE_EXT);
glColorTableEXT(GL_SHARED_TEXTURE_PALETTE_EXT, GL_RGBA8, image1->palette_width, GL_RGB, GL_UNSIGNED_BYTE, image1->palette);
// Create Texture
glGenTextures(1, &texture[0]);
glBindTexture(GL_TEXTURE_2D, texture[0]); // 2d texture (x and y size)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR); // scale linearly when image bigger than texture
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_LINEAR); // scale linearly when image smalled than texture
// 2d texture, level of detail 0 (normal), 3 components (red, green, blue), x size from image, y size from image,
// border 0 (normal), rgb color data, unsigned byte data, and finally the data itself.
glTexImage2D(GL_TEXTURE_2D, 0, GL_COLOR_INDEX8_EXT, image1->width, image1->height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, image1->data);
}
/* A general OpenGL initialization function. Sets all of the initial parameters. */
void InitGL(int Width, int Height) // We call this right after our OpenGL window is created.
{
LoadGLTextures();
glEnable(GL_TEXTURE_2D);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // This Will Clear The Background Color To Black
glClearDepth(1.0); // Enables Clearing Of The Depth Buffer
glDepthFunc(GL_LESS); // The Type Of Depth Test To Do
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glShadeModel(GL_SMOOTH); // Enables Smooth Color Shading
glMatrixMode(GL_PROJECTION);
glLoadIdentity(); // Reset The Projection Matrix
gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f); // Calculate The Aspect Ratio Of The Window
glMatrixMode(GL_MODELVIEW);
}
/* The function called when our window is resized (which shouldn't happen, because we're fullscreen) */
void ReSizeGLScene(int Width, int Height)
{
if (Height == 0) // Prevent A Divide By Zero If The Window Is Too Small
Height = 1;
glViewport(0, 0, Width, Height); // Reset The Current Viewport And Perspective Transformation
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f);
glMatrixMode(GL_MODELVIEW);
}
/* The main drawing function. */
void DrawGLScene()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
glLoadIdentity(); // Reset The View
glTranslatef(0.0f,0.0f,-5.0f); // move 5 units into the screen.
glRotatef(xrot,1.0f,0.0f,0.0f); // Rotate On The X Axis
glRotatef(yrot,0.0f,1.0f,0.0f); // Rotate On The Y Axis
glRotatef(zrot,0.0f,0.0f,1.0f); // Rotate On The Z Axis
glBindTexture(GL_TEXTURE_2D, texture[0]); // choose the texture to use.
glBegin(GL_QUADS); // begin drawing a cube
// Front Face (note that the texture's corners have to match the quad's corners)
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Top Left Of The Texture and Quad
// Back Face
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Bottom Left Of The Texture and Quad
// Top Face
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
// Bottom Face
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
// Right face
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
// Left Face
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
glEnd(); // done with the polygon.
xrot+=1.5f; // X Axis Rotation
yrot+=1.5f; // Y Axis Rotation
zrot+=1.5f; // Z Axis Rotation
//
// swap buffers to display, since we're double buffered.
glKosSwapBuffers();
}
int main(int argc, char **argv)
{
glKosInit();
InitGL(640, 480);
ReSizeGLScene(640, 480);
while(1) {
DrawGLScene();
}
return 0;
}