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Fix lines

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UnknownShadow200 2024-10-02 19:00:05 +10:00
parent a47f331cee
commit 19a76cbefd
4 changed files with 100 additions and 88 deletions
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171
GL/draw.c
View File

@ -442,17 +442,20 @@ static void genQuadStrip(Vertex* output, GLuint count) {
for (; count > 2; count -= 2) {
*dst = src[-1];
(*dst--).flags = GPU_CMD_VERTEX_EOL;
*dst-- = src[-2];
*dst-- = src[-3];
*dst-- = src[-2];
*dst-- = src[-4];
src -= 2;
}
}
#define TRIFAN_COUNT(count) (((count) - 2) * 3)
static void genTriangleFan(Vertex* output, GLuint count) {
Vertex* dst = output + (((count - 2) * 3) - 1);
Vertex* src = output + (count - 1);
Vertex* dst = output + TRIFAN_COUNT(count) - 1;
Vertex* src = output + count - 1;
// Triangles generated as {first vertex, prior vertex, current vertex}
// e.g. {v1, v2, v3, v4} produces {v1, v2, v3}, {v1, v3, v4}
for (; count > 2; count--) {
*dst = *src--;
(*dst--).flags = GPU_CMD_VERTEX_EOL;
@ -462,100 +465,111 @@ static void genTriangleFan(Vertex* output, GLuint count) {
}
#define POINTS_COUNT(count) ((count) * 4)
#define POINT_SIZE 0.5f
static void genPoints(Vertex* output, GLuint count) {
Vertex* dst = output + POINTS_COUNT(count) - 1;
Vertex* src = output + count - 1;
float half_size = HALF_POINT_SIZE;
// Expands v to { v + (-S/2,S/2), v + (S/2,S/2), v + (S/2,-S/2), (-S/2,-S/2) }
// Expands v to { v + (-S/2,S/2), v + (S/2,S/2), v + (-S/2,S/2), (S/2,-S/2) }
for (; count > 0; count--, src--) {
*dst = *src;
dst->flags = GPU_CMD_VERTEX_EOL;
dst->xyz[0] -= POINT_SIZE; dst->xyz[1] -= POINT_SIZE;
dst->xyz[0] -= half_size; dst->xyz[1] -= half_size;
dst--;
*dst = *src;
dst->xyz[0] += POINT_SIZE; dst->xyz[1] -= POINT_SIZE;
dst->xyz[0] += half_size; dst->xyz[1] -= half_size;
dst--;
*dst = *src;
dst->xyz[0] += POINT_SIZE; dst->xyz[1] += POINT_SIZE;
dst->xyz[0] -= half_size; dst->xyz[1] += half_size;
dst--;
*dst = *src;
dst->xyz[0] -= POINT_SIZE; dst->xyz[1] += POINT_SIZE;
dst->xyz[0] += half_size; dst->xyz[1] += half_size;
dst--;
}
}
static void genLines(Vertex* output, GLuint count) {
Vertex* dst = output + ((count/2) * 3) - 1;
Vertex* src = output + (count ) - 1;
// Heavily based on the pvrline example by jnmartin84
// Which is based on https://devcry.heiho.net/html/2017/20170820-opengl-line-drawing.html
static Vertex* draw_line(Vertex* dst, Vertex* v1, Vertex* v2) {
Vertex ov1 = *v1;
Vertex ov2 = *v2;
// TODO don't copy unless dst might overlap v1/v2
for (; count > 0; count -= 2) {
*dst = *src;
dst->flags = GPU_CMD_VERTEX_EOL;
dst--; src--;
// Essentially "expands" a line into a quad by
// 1) Calculating normal of the line from v1 to v2
// 2) Scaling normal by the line width
// 3) Offseting the endpoints wrt the scaled normal
float dx = ov2.xyz[0] - ov1.xyz[0];
float dy = ov2.xyz[1] - ov1.xyz[1];
*dst = *src;
dst--;
float inverse_mag = frsqrt((dx*dx) + (dy*dy)) * HALF_LINE_WIDTH;
float nx = -dy * inverse_mag;
float ny = dx * inverse_mag;
*dst = *src;
dst->xyz[1] += 5;
dst--; src--;
}
}
static void genLineStrip(Vertex* output, GLuint count) {
Vertex* dst = output + (((count - 1) * 3) - 1);
Vertex* src = output + (count - 1);
for (; count > 1; count--) {
*dst = *src;
dst->flags = GPU_CMD_VERTEX_EOL;
dst--; src--;
*dst = *src;
dst--;
*dst = *src;
dst->xyz[0] += 5;
dst->xyz[1] += 5;
dst--;
}
}
static void genLineLoop(Vertex* output, GLuint count) {
Vertex* dst = output + ((count * 3) - 1);
Vertex* src = output + (count - 1);
Vertex last = *src;
for (; count > 1; count--) {
*dst = *src;
dst->flags = GPU_CMD_VERTEX_EOL;
dst--; src--;
*dst = *src;
dst--;
*dst = *src;
dst->xyz[0] += 5;
dst->xyz[1] += 5;
dst--;
}
// Connect first and last points
*dst = last;
// Expand first endpoint both "up" and "down"
*dst = ov1;
dst->flags = GPU_CMD_VERTEX_EOL;
dst->xyz[0] += nx;
dst->xyz[1] += ny;
dst--;
*dst = *output;
*dst = ov1;
dst->xyz[0] -= nx;
dst->xyz[1] -= ny;
dst--;
*dst = *output;
dst->xyz[0] += 5;
dst->xyz[1] += 5;
// Expand second endpoint both "up" and "down"
*dst = ov2;
dst->xyz[0] += nx;
dst->xyz[1] += ny;
dst--;
*dst = ov2;
dst->xyz[0] -= nx;
dst->xyz[1] -= ny;
dst--;
return dst;
}
#define LINES_COUNT(count) (((count) / 2) * 4)
static void genLines(Vertex* output, GLuint count) {
Vertex* dst = output + LINES_COUNT(count) - 1;
Vertex* src = output + count - 1;
// Draws line using two vertices
for (; count >= 2; count -= 2, src -= 2) {
dst = draw_line(dst, src, src - 1);
}
}
#define LINE_STRIP_COUNT(count) (((count) - 1) * 4)
static void genLineStrip(Vertex* output, GLuint count) {
Vertex* dst = output + LINE_STRIP_COUNT(count) - 1;
Vertex* src = output + count - 1;
// Draws line using current and prior vertex
for (; count > 1; count--, src--) {
dst = draw_line(dst, src, src - 1);
}
}
#define LINE_LOOP_COUNT(count) ((count) * 4)
static void genLineLoop(Vertex* output, GLuint count) {
Vertex* dst = output + LINE_LOOP_COUNT(count) - 1;
Vertex* src = output + count - 1;
Vertex last = *src, first = *output;
// Draws line using current and prior vertex
for (; count > 1; count--, src--) {
dst = draw_line(dst, src, src - 1);
}
// Connect first and last vertex
draw_line(dst, &first, &last);
}
typedef void (*ReadPositionFunc)(const GLubyte*, GLubyte*);
@ -1222,27 +1236,14 @@ GL_FORCE_INLINE GLuint calcFinalVertices(GLenum mode, GLuint count) {
switch (mode) {
case GL_POINTS:
return POINTS_COUNT(count);
case GL_LINE_LOOP:
// Triangles generated as {prior vertex, current vertex, current vertex}
// plus one triangle to connect final and initial vertex
// e.g. {v1, v2, v3, v4} produces {v1, v1, v2}, {v2, v2, v3}, {v3, v3, v4}, {v4, v4, v1}
return count * 3;
return LINE_LOOP_COUNT(count);
case GL_LINE_STRIP:
// Triangles generated as {prior vertex, prior vertex, current vertex}
// e.g. {v1, v2, v3, v4} produces {v1, v1, v2}, {v2, v2, v3}, {v3, v3, v4}
return (count - 1) * 3;
return LINE_STRIP_COUNT(count);
case GL_LINES:
// Triangles generated as {first vertex, first vertex, second vertex}
// e.g. {v1, v2, v3, v4} produces {v1, v1, v2}, {v3, v3, v4}
return (count / 2) * 3;
return LINES_COUNT(count);
case GL_TRIANGLE_FAN:
// Triangles generated as {first vertex, prior vertex, current vertex}
// e.g. {v1, v2, v3, v4} produces {v1, v2, v3}, {v1, v3, v4}
return (count - 2) * 3;
return TRIFAN_COUNT(count);
case GL_QUAD_STRIP:
//return ((count - 2) / 2) * 4;

3
GL/private.h
View File

@ -320,6 +320,9 @@ void _glMatrixLoadModelViewProjection();
extern GLfloat DEPTH_RANGE_MULTIPLIER_L;
extern GLfloat DEPTH_RANGE_MULTIPLIER_H;
extern GLfloat HALF_LINE_WIDTH;
extern GLfloat HALF_POINT_SIZE;
Matrix4x4* _glGetProjectionMatrix();
Matrix4x4* _glGetModelViewMatrix();

9
GL/state.c
View File

@ -3,7 +3,8 @@
#include <stdio.h>
#include "private.h"
GLfloat HALF_LINE_WIDTH = 1.0f / 2.0f;
GLfloat HALF_POINT_SIZE = 1.0f / 2.0f;
static struct {
GLboolean is_dirty;
@ -773,7 +774,11 @@ GLAPI void APIENTRY glAlphaFunc(GLenum func, GLclampf ref) {
}
void glLineWidth(GLfloat width) {
_GL_UNUSED(width);
HALF_LINE_WIDTH = width / 2.0f;
}
void glPointSize(GLfloat size) {
HALF_POINT_SIZE = size / 2.0f;
}
void glPolygonOffset(GLfloat factor, GLfloat units) {

5
include/GL/gl.h
View File

@ -552,6 +552,10 @@ GLAPI GLvoid APIENTRY glRecti(GLint x1, GLint y1, GLint x2, GLint y2);
GLAPI GLvoid APIENTRY glRectiv(const GLint *v1, const GLint *v2);
#define glRectsv glRectiv
/* Primitive configuration */
GLAPI void APIENTRY glLineWidth(GLfloat width);
GLAPI void APIENTRY glPointSize(GLfloat size);
/* Enable / Disable Capability */
/* Currently Supported Capabilities:
GL_TEXTURE_2D
@ -742,7 +746,6 @@ GLAPI GLenum APIENTRY glGetError(void);
/* Non Operational Stubs for portability */
GLAPI void APIENTRY glAlphaFunc(GLenum func, GLclampf ref);
GLAPI void APIENTRY glLineWidth(GLfloat width);
GLAPI void APIENTRY glPolygonMode(GLenum face, GLenum mode);
GLAPI void APIENTRY glPolygonOffset(GLfloat factor, GLfloat units);
GLAPI void APIENTRY glGetTexParameterfv(GLenum target, GLenum pname, GLfloat *params);