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[cadcdev-svn-commits] [SCM] branch master updated. v2.0.0-1495-gfff864a4
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From: falcovorbis <fal...@us...> - 2024-08-19 05:00:49
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This is an automated email from the git hooks/post-receive script. It was
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the project "A pseudo Operating System for the Dreamcast.".
The branch, master has been updated
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from 9d115023ffc10996601a8e12fdb809cff2c5804f (commit)
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- Log -----------------------------------------------------------------
commit fff864a476bc3096afc0de1b515f1a4453a6caa5
Author: jnmartin84 <jnm...@gm...>
Date: Mon Aug 19 00:55:22 2024 -0400
Add an example of how to render lines with the PVR. (#714)
* Add PVR-accelerated line-rendering example.
* turns out the endpoint order condition check is simple
* cleanup vert swapping
* formatting and comments
* one missed spaces-to-tab
* remove copyright header until I figure out what is wanted
* fix remaining stray tab issues
* update comments and long lines
-----------------------------------------------------------------------
Summary of changes:
examples/dreamcast/pvr/Makefile | 3 +
.../{network/dns-client => pvr/pvrline}/Makefile | 7 +-
examples/dreamcast/pvr/pvrline/pvrline.c | 264 +++++++++++++++++++++
3 files changed, 271 insertions(+), 3 deletions(-)
copy examples/dreamcast/{network/dns-client => pvr/pvrline}/Makefile (82%)
create mode 100644 examples/dreamcast/pvr/pvrline/pvrline.c
diff --git a/examples/dreamcast/pvr/Makefile b/examples/dreamcast/pvr/Makefile
index 24812cfe..3cb67d66 100644
--- a/examples/dreamcast/pvr/Makefile
+++ b/examples/dreamcast/pvr/Makefile
@@ -6,6 +6,7 @@
all:
$(KOS_MAKE) -C plasma
+ $(KOS_MAKE) -C pvrline
$(KOS_MAKE) -C pvrmark
$(KOS_MAKE) -C pvrmark_strips
$(KOS_MAKE) -C pvrmark_strips_direct
@@ -18,6 +19,7 @@ all:
clean:
$(KOS_MAKE) -C plasma clean
+ $(KOS_MAKE) -C pvrline clean
$(KOS_MAKE) -C pvrmark clean
$(KOS_MAKE) -C pvrmark_strips clean
$(KOS_MAKE) -C pvrmark_strips_direct clean
@@ -30,6 +32,7 @@ clean:
dist:
$(KOS_MAKE) -C plasma dist
+ $(KOS_MAKE) -C pvrline dist
$(KOS_MAKE) -C pvrmark dist
$(KOS_MAKE) -C pvrmark_strips dist
$(KOS_MAKE) -C pvrmark_strips_direct dist
diff --git a/examples/dreamcast/network/dns-client/Makefile b/examples/dreamcast/pvr/pvrline/Makefile
similarity index 82%
copy from examples/dreamcast/network/dns-client/Makefile
copy to examples/dreamcast/pvr/pvrline/Makefile
index 0e010c5a..a834749b 100644
--- a/examples/dreamcast/network/dns-client/Makefile
+++ b/examples/dreamcast/pvr/pvrline/Makefile
@@ -1,8 +1,8 @@
# Put the filename of the output binary here
-TARGET = dns-client.elf
+TARGET = pvrline.elf
# List all of your C files here, but change the extension to ".o"
-OBJS = dns-client.o
+OBJS = pvrline.o
all: rm-elf $(TARGET)
@@ -18,8 +18,9 @@ $(TARGET): $(OBJS)
kos-cc -o $(TARGET) $(OBJS)
run: $(TARGET)
- $(KOS_LOADER) $(TARGET) -n
+ $(KOS_LOADER) $(TARGET)
dist: $(TARGET)
-rm -f $(OBJS)
$(KOS_STRIP) $(TARGET)
+
diff --git a/examples/dreamcast/pvr/pvrline/pvrline.c b/examples/dreamcast/pvr/pvrline/pvrline.c
new file mode 100644
index 00000000..ee6632fb
--- /dev/null
+++ b/examples/dreamcast/pvr/pvrline/pvrline.c
@@ -0,0 +1,264 @@
+/*
+ * KallistiOS ##version##
+ *
+ * examples/dreamcast/pvr/pvrline/pvrline.c
+ * Copyright (C) 2024 Jason Martin
+ *
+ * This example demonstrates the use of the PVR to draw lines with quads
+ * (as triangle strips).
+ * It also demonstrates the use of pvr_list_prim, interleaving the drawing of
+ * OPAQUE and TRANSPARENT polygons.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <kos.h>
+
+/* 512 kb vertex buffer size */
+#define VERTBUF_SIZE (512*1024)
+
+KOS_INIT_FLAGS(INIT_DEFAULT);
+
+/* enable OP and TR lists */
+pvr_init_params_t pvr_params = {
+{ PVR_BINSIZE_16, 0, PVR_BINSIZE_16, 0, 0 }, VERTBUF_SIZE, 1, 0, 0, 3
+};
+
+uint8_t __attribute__((aligned(32))) op_buf[VERTBUF_SIZE];
+uint8_t __attribute__((aligned(32))) tr_buf[VERTBUF_SIZE];
+
+/*
+ * given a vec3f_t representing the screen-space start of a line (x,y,z),
+ * a vec3f_t representing the screen-space end of a line (x,y,z),
+ * a color, a width, a pvr polygon list type and a pvr polygon header
+ * uses the PVR to draw a line with a triangle strip consisting of 4 vertices
+ * representing a quad
+*/
+void draw_pvr_line(vec3f_t *v1, vec3f_t *v2, float width, int color,
+ int which_list, pvr_poly_hdr_t *which_hdr);
+
+int main(int argc, char **argv)
+{
+ pvr_poly_hdr_t op_hdr, tr_hdr;
+ pvr_poly_cxt_t op_cxt, tr_cxt;
+
+ /* start and end points of a line in screen-space */
+ vec3f_t v1, v2;
+ /* red, green, blue and alpha color components */
+ int r, g, b, a;
+ /* packed color */
+ int color;
+ /* line width */
+ int width;
+ /* moving offset added or subtracted to x and y components of endpoints */
+ int offset;
+ /* number of lines to draw per frame */
+ int linecount = 1;
+
+ maple_device_t *controller;
+ cont_state_t *cont;
+
+ printf("---KallistiOS PVR Line-drawing Example---\n");
+ printf("Press DPAD UP to increase line count\n\t(up to a maximum of 1536"
+ " lines).\n");
+ printf("Press DPAD DOWN to decrease line count\n\t(down to a minimum of 1"
+ " line).\n");
+ printf("Press A to reset line count to 1.\n");
+ printf("Press Start to exit.\n");
+
+ srand(time(NULL));
+
+ vid_set_enabled(0);
+ vid_set_mode(DM_640x480, PM_RGB565);
+ pvr_init(&pvr_params);
+ vid_set_enabled(1);
+
+ /* polygon header setup, OP lines */
+ pvr_poly_cxt_col(&op_cxt, PVR_LIST_OP_POLY);
+ pvr_poly_compile(&op_hdr, &op_cxt);
+
+ /* polygon header setup, TR lines */
+ pvr_poly_cxt_col(&tr_cxt, PVR_LIST_TR_POLY);
+ pvr_poly_compile(&tr_hdr, &tr_cxt);
+
+ offset = 0;
+
+ while (true) {
+ controller = maple_enum_type(0, MAPLE_FUNC_CONTROLLER);
+ if (controller) {
+ cont = maple_dev_status(controller);
+ if (cont->buttons & CONT_DPAD_UP) {
+ if (linecount < 1536) {
+ linecount += 1;
+ }
+ } else if (cont->buttons & CONT_DPAD_DOWN) {
+ if (linecount > 1) {
+ linecount -= 1;
+ }
+ } else if (cont->buttons & CONT_A) {
+ linecount = 1;
+ } else if (cont->buttons & CONT_START) {
+ break;
+ }
+ }
+
+ pvr_wait_ready();
+ pvr_scene_begin();
+
+ /* set vertex buffers for pvr_list_prim use */
+ pvr_set_vertbuf(PVR_LIST_OP_POLY, op_buf, VERTBUF_SIZE);
+ pvr_set_vertbuf(PVR_LIST_TR_POLY, tr_buf, VERTBUF_SIZE);
+
+ /*
+ * incrementing offset added to endpoints
+ * make endpoints occasionally move to other side of screen
+ * from where they start
+ * force swaps in the line drawing routine
+ */
+ offset = (offset + 5) % 360;
+
+ for (int i = 0; i < linecount; i++) {
+ v1.x = rand() % 128;
+ v1.y = rand() % 64;
+ v1.z = 5;
+
+ v2.x = 500 + (rand() % 96);
+ v2.y = 400 + (rand() % 48);
+ v2.z = 5;
+
+ /*
+ * add an offset in the range [0,359] to v1 x and y
+ * x stays within [0,487]
+ * y stays within [0,422]
+ */
+ v1.x += offset;
+ v1.y += offset;
+
+ /*
+ * subtract an offset in the range [0,359] from v2 x and y
+ * x stays within [141,595]
+ * y stays within [40,447]
+ */
+ v2.x -= offset;
+ v2.y -= offset;
+
+ /*
+ * the above offset can move v2 to the left of v1
+ * this demonstrates that lines will always render correctly
+ * regardless of vertex order
+ */
+
+ /* generate a random RGBA color */
+ r = rand() % 256;
+ g = rand() % 256;
+ b = rand() % 256;
+ a = rand() % 256;
+
+ color = PVR_PACK_COLOR((float)a / 255.0f,
+ (float)r / 255.0f,
+ (float)g / 255.0f,
+ (float)b / 255.0f);
+
+ width = (rand() % 5) + 1;
+
+ /* interleaved use of PVR polygon list types */
+ if (a == 255) {
+ /*
+ * when alpha is fully opaque
+ * use the OP list
+ */
+ draw_pvr_line(&v1, &v2, width, color,
+ PVR_LIST_OP_POLY, &op_hdr);
+ } else {
+ /*
+ * when alpha is transparent at all
+ * use the TR list
+ */
+ draw_pvr_line(&v1, &v2, width, color,
+ PVR_LIST_TR_POLY, &tr_hdr);
+ }
+ }
+
+ pvr_scene_finish();
+ }
+}
+
+void draw_pvr_line(vec3f_t *v1, vec3f_t *v2, float width, int color,
+ int which_list, pvr_poly_hdr_t *which_hdr)
+{
+ pvr_vertex_t __attribute__((aligned(32))) line_verts[4];
+ pvr_vertex_t *vert = line_verts;
+
+ vec3f_t *ov1;
+ vec3f_t *ov2;
+
+ for (int i=0;i<4;i++) {
+ line_verts[i].flags = PVR_CMD_VERTEX;
+ line_verts[i].argb = color;
+ line_verts[i].oargb = 0;
+ }
+ line_verts[3].flags = PVR_CMD_VERTEX_EOL;
+
+ /*
+ * when first vertex is to the left of or vertical with second vertex
+ * they are already ordered
+ * otherwise
+ * swap endpoints
+ */
+ if(v1->x <= v2->x) {
+ ov1 = v1;
+ ov2 = v2;
+ } else {
+ ov1 = v2;
+ ov2 = v1;
+ }
+
+ /*
+ * https://devcry.heiho.net/html/2017/20170820-opengl-line-drawing.html
+ *
+ * get the normal to the line segment running from v1 to v2
+ * use normal to draw a quad covering the actual line segment
+ */
+ float dx = ov2->x - ov1->x;
+ float dy = ov2->y - ov1->y;
+
+ /*
+ * use the fast reciprocal square root function provided by KOS
+ * to get inverse of the magnitude of the normal
+ * multiply by half of the line width
+ * this scales the normal, making a quad with the requested line width
+ */
+ float inverse_magnitude = frsqrt((dx*dx) + (dy*dy)) *
+ ((float)width*0.5f);
+ float nx = -dy * inverse_magnitude;
+ float ny = dx * inverse_magnitude;
+
+ /* normal offset "down" from the first endpoint */
+ vert->x = ov1->x + nx;
+ vert->y = ov1->y + ny;
+ vert->z = ov1->z;
+ vert++;
+
+ /* normal offset "up" from the first endpoint */
+ vert->x = ov1->x - nx;
+ vert->y = ov1->y - ny;
+ vert->z = ov2->z;
+ vert++;
+
+ /* normal offset "down" from the second endpoint */
+ vert->x = ov2->x + nx;
+ vert->y = ov2->y + ny;
+ vert->z = ov1->z;
+ vert++;
+
+ /* normal offset "up" from the second endpoint */
+ vert->x = ov2->x - nx;
+ vert->y = ov2->y - ny;
+ vert->z = ov2->z;
+
+ /* submit the poly header and vertices to requested list */
+ pvr_list_prim(which_list, which_hdr, sizeof(pvr_poly_hdr_t));
+ pvr_list_prim(which_list, &line_verts, 4 * sizeof(pvr_vertex_t));
+}
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A pseudo Operating System for the Dreamcast.
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