cd ..cd ..

[plz.git] / plzpart-gl / vga.c

diff --git a/plzpart-gl/vga.c b/plzpart-gl/vga.c
new file mode 100755 (executable)
index 0000000..f817e25
--- /dev/null
+++ b/plzpart-gl/vga.c
@@ -0,0 +1,126 @@
+/*
+ * Written by Nick Kovac with minor changes by Claudio Matsuoka
+ */
+
+#include <string.h>
+#include "common.h"
+
+static int plane_select[4] = { 0, 0, 0, 0 };
+static int line_compare = 0;
+static int hscroll_offset = 0;
+static uint8_t palette[256 * 3];
+
+#define SCREEN_WIDTH 320
+#define SCREEN_HEIGHT 400
+#define FRAME_BUFFER_WIDTH 384
+#define FRAME_BUFFER_HEIGHT 400
+
+uint8_t fb[FRAME_BUFFER_WIDTH * FRAME_BUFFER_HEIGHT];
+
+
+void vga_select_bitplanes_02()
+{
+       plane_select[0] = 1;
+       plane_select[1] = 0;
+       plane_select[2] = 1;
+       plane_select[3] = 0;
+}
+
+void vga_select_bitplanes_13()
+{
+       plane_select[0] = 0;
+       plane_select[1] = 1;
+       plane_select[2] = 0;
+       plane_select[3] = 1;
+}
+
+void vga_select_bitplanes_0123()
+{
+       plane_select[0] = 1;
+       plane_select[1] = 1;
+       plane_select[2] = 1;
+       plane_select[3] = 1;
+}
+
+void vga_write32(int offset, int val)
+{
+       int i, j;
+
+       // For each selected plane, calculate 4 pixel offsets and write 4 bytes.
+       // offset = 0, 4, 8, etc
+
+       for (i = 0; i < 4; i++) {
+               if (plane_select[i]) {
+                       for (j = 0; j < 4; j++) {
+                               // Get byte to write.
+                               uint8_t b = (val >> (j * 8));
+
+                               // Calculate offset.
+                               int fb_offs = i + (offset + j) * 4;
+
+                               // Write pixel.
+                               fb[fb_offs] = b;
+                       }
+               }
+       }
+}
+
+void vga_set_line_compare(int y)
+{
+       line_compare = y;
+}
+
+void vga_set_palette_entry(int index, int r, int g, int b)
+{
+       index *= 3;
+       palette[index++] = r;
+       palette[index++] = g;
+       palette[index] = b;
+}
+
+extern unsigned char *image;   // The OpenGL background image texture
+
+void vga_show_framebuffer()
+{
+       int x, y;
+
+       int nFirstLineIndex = line_compare + 1;
+
+       // Plot the palettised frame buffer.
+       unsigned int *ptr = fb;
+
+       // Clear the screen.
+       memset(image, 0, FRAME_BUFFER_WIDTH * FRAME_BUFFER_HEIGHT * 3);
+
+       copper1();
+       copper2();
+
+       for (y = nFirstLineIndex; y < SCREEN_HEIGHT; y++) {
+               for (x = 0; x < SCREEN_WIDTH; x++) {
+                       //ASSERT(x + hscroll_offset < FRAME_BUFFER_WIDTH);
+                       uint8_t r, g, b;
+                       int idx = ptr[x + hscroll_offset] * 3;
+
+                       r = palette[idx++];
+                       g = palette[idx++];
+                       b = palette[idx];
+
+                       int ofs = (y * 320 + x) * 3;
+                       image[ofs++] = r << 2;
+                       image[ofs++] = g << 2;
+                       image[ofs]   = b << 2;
+               }
+
+               ptr += FRAME_BUFFER_WIDTH;
+       }
+}
+
+void vga_set_hscroll_offset(int offset)
+{
+       hscroll_offset = offset;
+}
+
+void vga_upload_palette(uint8_t *pal)
+{
+       memcpy(palette, pal, 256 * 3);
+}