Add a mipmap sample

samples/Makefile

@@ -28,3 +28,4 @@ all:
 	$(KOS_MAKE) -C polymark all
 	$(KOS_MAKE) -C polygon_offset all
 	$(KOS_MAKE) -C blend_test all
+	$(KOS_MAKE) -C mipmap all

samples/mipmap/Makefile

@@ -0,0 +1,29 @@
+TARGET = mipmap.elf
+OBJS = main.o
+
+all: rm-elf $(TARGET)
+
+include $(KOS_BASE)/Makefile.rules
+
+clean:
+	-rm -f $(TARGET) $(OBJS) romdisk.*
+
+rm-elf:
+	-rm -f $(TARGET) romdisk.*
+
+$(TARGET): $(OBJS) romdisk.o
+	$(KOS_CC) $(KOS_CFLAGS) $(KOS_LDFLAGS) -o $(TARGET) $(KOS_START) \
+		$(OBJS) romdisk.o $(OBJEXTRA) -lm -lkosutils $(KOS_LIBS)
+
+romdisk.img:
+	$(KOS_GENROMFS) -f romdisk.img -d romdisk -v
+
+romdisk.o: romdisk.img
+	$(KOS_BASE)/utils/bin2o/bin2o romdisk.img romdisk romdisk.o
+
+run: $(TARGET)
+	$(KOS_LOADER) $(TARGET)
+
+dist:
+	rm -f $(OBJS) romdisk.o romdisk.img
+	$(KOS_STRIP) $(TARGET)

samples/mipmap/main.c

@@ -0,0 +1,216 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "gl.h"
+#include "glu.h"
+#include "glkos.h"
+
+extern uint8 romdisk[];
+KOS_INIT_ROMDISK(romdisk);
+
+/* storage for one texture  */
+int texture[1];
+
+/* Image type - contains height, width, and data */
+struct Image {
+    unsigned long sizeX;
+    unsigned long sizeY;
+    char *data;
+};
+typedef struct Image Image;
+
+// quick and dirty bitmap loader...for 24 bit bitmaps with 1 plane only.
+// See http://www.dcs.ed.ac.uk/~mxr/gfx/2d/BMP.txt for more info.
+int ImageLoad(char *filename, Image *image) {
+    FILE *file;
+    unsigned long size;                 // size of the image in bytes.
+    unsigned long i;                    // standard counter.
+    unsigned short int planes;          // number of planes in image (must be 1)
+    unsigned short int bpp;             // number of bits per pixel (must be 24)
+    char temp;                          // temporary color storage for bgr-rgb conversion.
+
+    // make sure the file is there.
+    if ((file = fopen(filename, "rb"))==NULL)
+    {
+        printf("File Not Found : %s\n",filename);
+        return 0;
+    }
+
+    // seek through the bmp header, up to the width/height:
+    fseek(file, 18, SEEK_CUR);
+
+    // read the width
+    if ((i = fread(&image->sizeX, 4, 1, file)) != 1) {
+        printf("Error reading width from %s.\n", filename);
+        return 0;
+    }
+    printf("Width of %s: %lu\n", filename, image->sizeX);
+
+    // read the height
+    if ((i = fread(&image->sizeY, 4, 1, file)) != 1) {
+        printf("Error reading height from %s.\n", filename);
+        return 0;
+    }
+    printf("Height of %s: %lu\n", filename, image->sizeY);
+
+    // calculate the size (assuming 24 bits or 3 bytes per pixel).
+    size = image->sizeX * image->sizeY * 3;
+
+    // read the planes
+    if ((fread(&planes, 2, 1, file)) != 1) {
+        printf("Error reading planes from %s.\n", filename);
+        return 0;
+    }
+    if (planes != 1) {
+        printf("Planes from %s is not 1: %u\n", filename, planes);
+        return 0;
+    }
+
+    // read the bpp
+    if ((i = fread(&bpp, 2, 1, file)) != 1) {
+        printf("Error reading bpp from %s.\n", filename);
+        return 0;
+    }
+    if (bpp != 24) {
+        printf("Bpp from %s is not 24: %u\n", filename, bpp);
+        return 0;
+    }
+
+    // seek past the rest of the bitmap header.
+    fseek(file, 24, SEEK_CUR);
+
+    // read the data.
+    image->data = (char *) malloc(size);
+    if (image->data == NULL) {
+        printf("Error allocating memory for color-corrected image data");
+        return 0;
+    }
+
+    if ((i = fread(image->data, size, 1, file)) != 1) {
+        printf(stderr, "Error reading image data from %s.\n", filename);
+        return 0;
+    }
+
+    for (i=0;i<size;i+=3) { // reverse all of the colors. (bgr -> rgb)
+        temp = image->data[i];
+        image->data[i] = image->data[i+2];
+        image->data[i+2] = temp;
+    }
+
+    // we're done.
+    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 (!ImageLoad("/rd/NeHe.bmp", image1)) {
+        exit(1);
+    }
+
+    // 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_MIPMAP_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, 3, image1->sizeX, image1->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, image1->data);
+
+    glGenerateMipmapEXT(GL_TEXTURE_2D);
+};
+
+/* 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);
+}
+
+void DrawQuad() {
+    glBegin(GL_QUADS);
+    glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 0.0f);	// Bottom Left Of The Texture and Quad
+    glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 0.0f);	// Bottom Right Of The Texture and Quad
+    glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, 0.0f);	// Top Right Of The Texture and Quad
+    glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, 0.0f);	// Top Left Of The Texture and Quad
+    glEnd();                                    // done with the polygon.
+}
+
+/* The main drawing function. */
+void DrawGLScene()
+{
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    glLoadIdentity();
+    glClearColor(0.5, 0.5, 0.5, 1.0);
+
+    glBindTexture(GL_TEXTURE_2D, texture[0]);
+
+    glTranslatef(-1.5f, 0.0f, -4.5f);
+    DrawQuad();
+
+    glTranslatef(1.0f, 0.0f, -5.0f);
+    DrawQuad();
+
+    glTranslatef(1.5f, 0.0f, -5.0f);
+    DrawQuad();
+
+    glTranslatef(2.0f, 0.0f, -5.0f);
+    DrawQuad();
+
+    glTranslatef(3.5f, 0.0f, -5.0f);
+    DrawQuad();
+
+    glKosSwapBuffers();
+}
+
+int main(int argc, char **argv)
+{
+    glKosInit();
+
+    InitGL(640, 480);
+    ReSizeGLScene(640, 480);
+
+    while(1) {
+        DrawGLScene();
+    }
+
+    return 0;
+}